JP4148723B2 - Image recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image recording apparatus such as a printer, a copying machine, and a facsimile machine.
[0002]
[Prior art]
For example, an electrophotographic printer forms an electrostatic latent image by selectively irradiating light to a charged photosensitive drum in accordance with print information, and developing the electrostatic latent image by attaching toner to the electrostatic latent image. A toner image is formed, and the toner image is transferred to a sheet and fixed.
[0003]
FIG. 30 is a block diagram of a printer control circuit in a conventional electrophotographic printer, and FIGS. 31 and 32 are time charts at the time of printing of the conventional electrophotographic printer. In FIG. 30, reference numeral 1 denotes a print control unit including a microprocessor, a ROM, a RAM, an input / output port, a timer, and the like. The printing control unit 1 is arranged inside the printing unit of the printer, and the entire printer is sequence-controlled by a control signal SG1, a video signal (one-dimensional arrangement of dot map data) SG2, etc. from a host controller (not shown). And print operation.
[0004]
When the printing instruction is received by the control signal SG1, the printing control unit 1 first detects whether or not the fixing device 77 including the heater 77a is within a usable temperature range by using the fixing device temperature sensor 75, and the temperature range. If not, the heater 77a is energized to heat the fixing device 77 to a usable temperature. Next, the development / transfer process motor (PM) 68 is rotated via a driver 67, and at the same time, the charging high-voltage power supply 63 is turned on by the charge signal SGC, and a voltage is applied to the charger 64.
[0005]
Then, the presence / absence and type of a sheet (not shown) set is detected by a remaining sheet sensor 73 and a sheet size sensor 74. A paper feed motor (PM) 70 can be rotated in both directions via a driver 69. The paper feed motor (PM) is reversely rotated first and feeds the set paper by a preset amount until it is detected by the paper inlet sensor 71. . Subsequently, the paper is rotated forward to convey the paper into a printing mechanism inside the printer.
[0006]
When the paper reaches the printable position, the print control unit 1 transmits a timing signal SG3 (including a main scanning synchronization signal and a sub-scanning synchronization signal) to the host controller and receives a video signal SG2. The video signal SG2 edited for each page in the upper controller and received by the print control unit 1 is transferred to the LED head 78 as the print data signal HD-DATA. The LED head 78 is formed by arranging a plurality of LEDs provided for printing one dot (pixel).
[0007]
When the print control unit 1 receives a video signal for one line, the print control unit 1 transmits a latch signal HD-LOAD to the LED head 78 and causes the LED head 78 to hold the print data signal HD-DATA. Thus, the print control unit 1 can perform printing according to the print data signal HD-DATA held in the LED head 78 even while the next video signal SG2 is being received from the host controller. HD-CLK is a clock signal for transmitting the print data signal HD-DATA to the LED head 78. Transmission / reception of the video signal SG2 is performed for each print line.
[0008]
The information printed by the LED head 78 is formed into a latent image as a dot with an increased potential (approximately 0 V) on a photosensitive drum (not shown) charged to a negative potential. In the developing unit, the toner for image formation charged to a negative potential is electrically attracted to each dot by the attraction force, and a toner image is formed. Thereafter, the toner image is sent to the transfer device 66, while the transfer signal SG4 turns on the high-voltage power supply 65 for positive transfer, and the transfer device 66 passes through the interval between the photosensitive drum and the transfer device 66. Transfer the toner image on top.
[0009]
The sheet having the transferred toner image is conveyed in contact with a fixing device 77 having a built-in heater 77a, and is fixed to the paper by the heat of the fixing device 77. The sheet having the fixed image is further conveyed and discharged from the printer printing mechanism through the sheet discharge port sensor 72 to the outside of the printer. In response to detection by the paper size sensor 74 and the paper inlet sensor 71, the print control unit 1 applies the voltage from the transfer high-voltage power supply 65 to the transfer device 66 only while the paper passes through the transfer device 66. When printing is completed and the sheet passes the sheet discharge port sensor 72, the application of voltage to the charger 64 by the charging high-voltage power supply 63 is terminated, and at the same time, the rotation of the development / transfer process motor 68 is stopped. Thereafter, the above operation is repeated.
[0010]
Next, the LED head 78 will be described. FIG. 33 is a diagram showing a general circuit configuration of the LED head. As shown in the figure, the print data signal HD-DATA is input to the LED head 78 together with the clock signal HD-CLK. For example, in a printer having a resolution of 600 dots per inch that can be printed on A4 size paper, bit data for 4992 dots is stored in the flip-flop circuit FF. ₁ , FF ₂ , ..., FF ₄₉₉₂ Are sequentially transferred. Next, a latch signal HD-LOAD is input to the LED head 78, and the bit data is stored in each latch circuit LT. _l , LT ₂ , ..., LT ₄₉₉₂ Is latched on. Subsequently, the light emitting element LD is generated by the bit data and the print drive signal HD-STB-N. _l , LD ₂ , ..., LD ₄₉₉₂ Among them, the one corresponding to the dot data at the HIGH (high) level is turned on. G ₀ Is NOR gate, G ₁ , G ₂ , ..., G ₄₉₉₂ Is a NAND gate circuit, TR ₁ , TR ₂ , ..., TR ₄₉₉₂ Is the switch element, V _DD Is the power supply.
[0011]
Next, the structure of the LED head and the converging rod lens array will be described. FIG. 34 is a diagram showing a general structure of the LED head and the lens array. As shown in FIG. 34, the LED head 78 includes a printed circuit board 27 in which LED chips 28 on which LED light emitting portions are formed and driver IC chips 79 for driving them are linearly arranged, and light output from the light emitting elements. And a lens array 29 for condensing the light. The lens array 29 collects light from the light emitting elements and forms an image on the photosensitive drum, and is formed by arranging a plurality of rod lenses at an equal pitch.
[0012]
MTF (Modulation Transfer Function) is one that shows the characteristics of the lens array 29. Hereinafter, the MTF will be described with reference to FIG. MTF is one method for expressing the characteristics of an optical system using frequency characteristics, and indicates how the spatial frequency spectrum (amplitude) changes between the input side and the output side. As the MTF, an image of a rectangular wave lattice pattern is received by a CCD image sensor, and the MTF as a response function of SLA can be calculated from the light amount level by the following equation.
[0013]
MTF (w) = (i (w) max−i (w) min) / (i (w) max + i (w) min) × 100 (%)
Here, i (w) max and i (w) min represent the maximum value and the minimum value of the rectangular wave response at the spatial frequency w (lp / mm), respectively. An example of the MTF value obtained by measuring the light amount level at each dot position of the LED head is shown in FIG.
[0014]
FIGS. 37A and 37B show light intensity distributions when three adjacent light emitting elements emit light. As shown in FIG. 37, the light intensity distribution of each element of each light emitting element (LED) can be approximated by a Gaussian distribution.
[0015]
In FIG. 37A, curves a1 to a3 indicate the light intensity distribution of each dot, and curve b indicates the light intensity distribution when the light of each dot is synthesized. As shown in the figure, when adjacent light emitting elements emit light, each light influences each other, resulting in a distribution as intensifying curve b. The same applies to the curves a1 to a3 and the curve b in FIG.
[0016]
[Problems to be solved by the invention]
Even when the dot diameters of the respective light emitting elements are made uniform, depending on the value of MTF, when adjacent light emitting elements emit light, the respective lights influence each other and strengthen each other. FIG. 37 (a) is a diagram showing a case where the MTF value is low. When the MTF is low, it is difficult to obtain a sharp image, and the spot diameter in the image formation part is the light of the dot located at the center. This affects the adjacent dots of the dots located in the portion, and the spot diameter of both adjacent dots becomes large. FIG. 37B is a diagram showing a case where the MTF value is high. When the MTF is high, the image formation becomes too sharp, and the light of the dot diameters on both sides is combined with the dot at the center, and the center The spot diameter of the dots in the part becomes large. That is, the combined light emission distribution is distorted whether the MTF is large or small as described above.
[0017]
Conventionally, in order to correct the variation in dot diameter due to the variation of each light emitting element, each light emitting element is caused to emit light, and the light emission intensity at that time is measured, and each light emission is made so that all the light emitting elements have the same light emission intensity. Data supplied to the element was individually corrected according to correction data obtained from the measurement results. However, in such a correction, when each light emitting element emits light alone, the dot diameter becomes equal to a predetermined set value, but when adjacent light emitting elements also emit light simultaneously, the dot diameter deviates from the set value. There is a light emitting element, and as a result, there is a problem that variation in dot diameter is not sufficiently eliminated.
[0018]
The reason for this is that, as described with reference to FIG. 37, the light distribution of each LED element is affected by the light distribution of the adjacent light emitting elements. Because it varies depending on slight variations in pitch, even if the individual spot diameters are constant, the combined distribution is a combination of adjacent dots with different light emission distributions, so the combined imaging surface spot diameters will be different. is there. As a result, the electrostatic latent image formed on the photosensitive drum is distorted, causing a problem that the toner image is deformed and print quality is deteriorated.
[0019]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an image recording apparatus capable of suppressing variation in dot diameter due to the influence of adjacent or adjacent light emitting elements.
[0020]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1 A charged photoconductor Multiple driven elements An electrostatic latent image is formed by exposing with a toner, and printing is performed by transferring a toner image formed by developing the electrostatic latent image to a recording medium. In the image recording device,
Storage means for storing drive data for driving the driven elements for each driven element;
Drive data of each of the driven element corresponding to the target dot and the driven element corresponding to at least one other dot in the predetermined area including the target dot is read from the storage unit, and the read drive data and the external data A calculation unit that generates corrected print data from the print data of the target dot input from the control unit;
The calculation means obtains a sum of drive data values of driven elements corresponding to dots to be printed among the dots in the predetermined area, and divides the obtained sum by the number of dots to be printed. The average value of the drive data value of the driven element corresponding to each dot in the predetermined area is obtained by subtracting the drive data value of the driven element corresponding to the target dot from the average value, and the subtraction result , The value obtained by adding the print data value of the dot of interest is the value of the corrected print data,
Printing is performed by driving the driven element corresponding to the target dot using the corrected print data.
[0021]
The calculation means may average the drive data of each dot in a predetermined area including the target dot. The print data may be binary data or multi-value data.
[0022]
The predetermined region is a region including a target dot and an adjacent dot of the target dot, and the calculation means inputs the drive data of the driven element corresponding to the target dot and the adjacent dot, respectively, and the target dot input from the control unit The corrected print data may be generated based on the print data.
[0023]
The predetermined area is an area including a target dot, an adjacent dot of the target dot, and a dot adjacent to the adjacent dot, and the calculation means corresponds to the target dot, the adjacent dot, and a dot adjacent to the adjacent dot, respectively. The corrected print data may be generated based on the drive data of the drive element and the print data of the target dot input from the control unit.
[0024]
The predetermined area is an area where dots to be printed are continuous including the target dot, and the calculation means corresponds to the drive data of the driven element corresponding to the target dot and the dot located at the end of the predetermined area. The corrected print data may be generated based on the drive data of the driven element and the print data of the target dot input from the control unit.
[0027]
The driven element may be a gradation LED element.
The driven element is a light emitting element, and includes a condensing member that condenses light emitted from the light emitting element, and the driving data stored in the memory is data based on light intensity obtained through the condensing member. May be.
A table in which light intensity and dot diameter are associated may be provided, and the drive data may be dot diameter data obtained by associating the intensity of light collected on the light collecting member with the dot diameter of the table. .
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 shows the configuration of Embodiment 1 of the image recording apparatus of the present invention. As shown in the figure, the apparatus includes a print control unit 1, a print data correction circuit 3, a gradation LED head 4, and a nonvolatile storage element (for example, EEPROM) ROM 2. A video signal including print data and a control signal for controlling the operation of the print data correction circuit 3 are output from the print control unit 1 to the print data correction circuit 3. A timing signal for synchronizing the print control unit 1 and the print data correction circuit 3 is output from the print data correction circuit 3 to the print control unit 1. Corrected print data output from the print data correction circuit 3 to the gradation LED head 4 in synchronization with the timing signal, a latch signal for holding the corrected print data in the LED head 4, and a clock signal are output. Is done. The ROM 2 connected to the print data correction circuit 3 is for storing dot diameter data based on the measurement result for each dot of the spot diameter on the imaging surface of the gradation LED head 4.
[0029]
Next, the configuration of the print data correction circuit 3 will be described with reference to FIG. As shown in the figure, the print data correction circuit 3 includes a buffer 11, a one-line reception buffer 12, a selector 13, a reception address circuit 14, a transmission address circuit 15, a timing generation circuit 16, latches 18 to 23, and a logical operation circuit 24. , Dot counter 17, line counter 25, and control circuit 26. The 1-line reception buffer 12 is connected to the input and output of the buffer 11 that receives the video signal from the print control unit 1 and the output of the selector 13. Two inputs of the selector 13 are connected to the output of the reception address circuit 14 and the output of the transmission address circuit 15, respectively. The buffer switching signal that is the output of the selector 13 is supplied to the buffer 11. The input of the reception address circuit 14 is connected to the output of the timing generation circuit 16, and the input of the transmission address circuit 15 is connected to the output of the dot counter 17. The timing generation circuit 16 supplies a timing signal to the print control unit 1, and the print control unit 1 supplies a control signal to the timing generation circuit 16.
[0030]
A transfer clock signal is output from the timing generation circuit 16 to the gradation LED head 4, the latches 18 to 23, and the dot counter 17. A latch signal is also output from the timing generation circuit 16 to the gradation LED head 4. The output of the latch 18 is connected to the input of the latch 19 and the input of the logic operation circuit 24, the output of the latch 19 is connected to the input of the latch 20 and the input of the logic operation circuit 24, and the output of the latch 20 is connected to the input of the logic operation circuit 24. Connected to input. The buffer 11 is connected to the input of the latch 18. The output of the latch 21 is connected to the input of the latch 22 and the input of the logic operation circuit 24, and the output of the latch 22 is connected to the input of the latch 23 and the input of the logic operation circuit 24. The output of the latch 23 is connected to the input of the logic operation circuit 24.
[0031]
The ROM 2 is connected to the input of the latch 21 and the output of the dot counter 17 respectively. The data lines from the ROM 2 through the latches 21 to 23 to the logical operation circuit 24 are composed of four signal lines so that 4-bit parallel dot diameter data can be transmitted. The control circuit 26 is connected to the output of the raster line counter 25, the output of the logic operation circuit 24, and the input of the gradation LED head 4. The data line from the logical operation circuit 24 to the gradation LED head 4 via the control circuit 26 is composed of four signal lines so that 4-bit parallel print data can be transmitted. The line counter 25 is supplied with a latch signal so that the number of lines for one page can be counted.
[0032]
FIG. 3 shows the configuration of the logical operation circuit 24. As shown in the figure, the logical operation circuit 24 includes AND gates 37 to 48, adders 49a and 49b, a divider 50, a subtractor 55, and AND gates 51 to 54.
[0033]
The AND gates 37 to 40 are supplied with print data from the latch 18 and 4-bit dot diameter data from the latch 21. The AND gates 41 to 44 are supplied with print data from the latch 19 and 4-bit dot diameter data from the latch 22. The AND gates 45 to 48 are supplied with print data from the latch 20 and 4-bit dot diameter data from the latch 23. The outputs of the AND gates 37 to 40, the outputs of the AND gates 41 to 44, and the outputs of the AND gates 45 to 48 are supplied to the adder 49a. The outputs of the latches 18 to 20 are also supplied to the adder 49a. The outputs of the AND gates 41 to 44 are also supplied to the subtracter 55 and the adder 49b. The adder 49a supplies the divider 50 with 5-bit dot diameter data and 2-bit dot number data described later. The subtractor 55 supplies the difference between the division result of the divider 50 and the outputs of the AND gates 41 to 44 to the adder 49b. The adder 49b adds the output of the subtractor 55 and the outputs of the AND gates 41 to 44. The addition result of the adder 49b and the print data from the latch 19 are supplied to the AND gates 51 to 54. Outputs of the ANDs 51 to 54 are supplied to the control circuit 26 as print data.
[0034]
Next, the gradation LED head 4 will be described with reference to FIGS. The gradation LED head 4 can set the value of the drive current supplied to the light emitting element (LED) for each dot, that is, the light emitting element, based on the 4-bit input data. Amount) can be varied for each dot. There is a linear relationship between 4-bit data supplied to the gradation LED head 4 and the LED drive current value as shown in FIG.
[0035]
On the other hand, when the LED drive current value is changed, the light emission power of the LED (that is, the exposure amount to the photosensitive drum) changes, and the print density changes as shown in FIG. When the 4-bit input data is small, that is, when the light emission energy of the LED is small, an electrostatic latent image and a toner image having a small dot diameter are formed as shown in FIG. When the 4-bit input data is increased, that is, when the emission energy of the LED is increased, an electrostatic latent image and a toner image having a large dot diameter are formed as shown in FIG. Thus, when the light emission energy of the LED is changed, the dot area to be printed changes, and within the set current range, the dot area can be freely changed within the current adjustment step width. .
[0036]
In this embodiment, when the data supplied to the gradation LED head 4 is “1000 (08H)”, the standard current value (standard density) is used, and when it is “0000 (00H)”, the drive current is supplied to the LED. Without (density 0), the LED drive current increases as the input data increases to “0001 (01H)” and “0010 (02H)”. When “1111”, the maximum drive current is supplied and the print density is increased. I try to maximize it. Note that H represents hexadecimal notation.
[0037]
Hereinafter, the operation of the apparatus of the first embodiment having the above configuration will be described in detail with reference to the drawings. In FIG. 1, when printing preparation is completed, the print control unit 1 transmits a timing signal to a host controller (not shown) and receives a video signal edited for each page by the host controller. This video signal is sent to the print data correction circuit 3 from the print controller 1 together with the control signal. The print data correction circuit 3 shown in FIG. 2 performs the following processing on this video signal. That is, the timing generation circuit 16 that has received the control signal generates a reception clock signal and sends it to the reception address circuit 14. The video signal received by the buffer 11 is stored at an address in the one-line reception buffer 12 designated by the reception address circuit 14 in synchronization with the reception clock signal. The video signal is stored in the one-line reception buffer 12 every time a video signal for one line is received from the host controller.
[0038]
When the transmission address circuit 15 designates a column address in the one-line reception buffer 12, the data at that address is latched in the latches 18 to 20, and logically expressed as three consecutive columns of data (adjacent three dots of data). Input to the arithmetic circuit 24. Until all the data in the 1-line reception buffer 12 is latched, the dot counter 17 increments a count value indicating what number of dots the data to be latched is. The dot counter 17 also sends to the ROM 2 the address where the dot diameter data input to the logic operation circuit 24 is stored. As a result, data is input to the logical operation circuit 24 and simultaneously, the dot diameter data of the data is input from the ROM 2 via the latch 21. The logical operation circuit 24 performs correction printing consisting of 4 bits per dot for the center dot of the input 3 columns of data from the input 3 columns of 1 bit data and the 4-bit dot diameter data. Calculate the data.
[0039]
Here, the dot diameter data stored in the ROM 2 will be described. In order to obtain dot diameter data, a light intensity meter is first placed at the position of the image plane of light emitted from the gradation LED head 4. That is, the light intensity meter is disposed at a position away from the gradation LED head 4 by the same distance as the distance between the gradation LED head 4 and the photosensitive drum. Next, the light emitting element (LED) to be measured is caused to emit light, and the dot diameter of the light emitting element to be measured is obtained from the intensity of light at that time. This is performed for all the light emitting elements of the gradation LED head 4. Hereinafter, the procedure for measuring the light intensity will be described in more detail with reference to FIG.
[0040]
In FIG. 6, 27 is an LED head substrate, 28 is an LED light emitting element, 29 is a lens array, and 31 is a light intensity meter. The output of the light intensity meter is input to the image processing circuit 35 and measured as the light intensity of one dot on the imaging surface, and the dot diameter data is obtained from a table in which the light intensity and the dot diameter obtained in advance through experiments are associated with each other. Is converted to The dot diameter data converted by the image processing circuit 35 is sent to the ROM writer 36 and written at a predetermined address in the ROM 2. Since the measurement is performed sequentially from the light emitting element at the end of the LED head 4 to the opposite end, the dot is sequentially stored in the ROM from the dot diameter data of the light emitting element at the end of the LED head 4.
[0041]
Reference numeral 33 denotes a control circuit for controlling the light emission of the LED head 4, 32 is a motor for moving the light intensity meter, and 34 is a motor controller for controlling the motor 32. The motor 32 is driven by the motor controller 34 and the light intensity meter 3 1 is moved along the guide 30 from the light emitting element at one end of the LED head 4 to the position of the light emitting element at the other end. At this time, the control circuit 33 causes the light emitting element to be measured of the LED head 4, that is, the LED light emitting element 28 facing the light intensity meter to emit light. The gradation data at the time of measurement is, for example, data of 08H (center value) in hexadecimal notation.
[0042]
At this time, the image obtained by the light intensity meter 31 is sent to the image processing circuit 35. Next, the motor 32 is driven by the motor controller 34, the light intensity meter 31 is moved to the position of the adjacent light emitting element, and the control circuit 33 causes the light emitting element at the new position and the adjacent light emitting elements on both sides thereof to emit light. An image is captured by the intensity meter 31. Conversion is made as dot diameter data based on a table in which the light intensity and dot diameter of the image obtained in this way are associated with each other. This procedure is repeated for all the dots, and the dot diameter data of all the light emitting elements of the LED head 4 is obtained.
[0043]
After obtaining the dot diameter data of all the light emitting elements of the LED head 4, the average value of the measured dot diameters is calculated. As described with reference to FIG. 4, in this embodiment, by changing the gradation data supplied to the gradation LED head 4, it is possible to change the dot density, that is, the dot diameter in dot units. Further, the gradation data value and the dot diameter are in a proportional relationship. Therefore, the dot diameter of the dot when the data of 08H (center value) in hexadecimal notation is sent to the gradation LED head 4 for printing is set to be the average value of the measured dot diameters. The dot diameter at this time is S8.
[0044]
If the change in dot diameter when the gradation data is changed by one step from 08H to 09H by 01H is ΔS, the change in dot diameter when each gradation data in the range of 01H to 0FH is changed by one step. The minute is also almost ΔS. Therefore, dot diameter data of 8 + 1 = 9 is given to a dot whose dot diameter is larger than the average value by ΔS. Further, dot diameter data of 8−2 = 6 is given to dots whose dot diameter is smaller by 2ΔS than the average value. When the correction data as described above is given, the gradation data and the dot diameter data have a relationship as shown in FIG. Using this relationship, the measured dot diameter is converted into dot diameter data in the range of 1 to 15. In the same manner, the dot diameters of all the light emitting elements of the LED head 4 are measured, the values are converted into dot diameter data, and are sequentially written in the ROM 2.
[0045]
Next, the operation of the logical operation circuit 24 will be described in detail. In FIG. 3, simultaneously with the print data being input to the latch 18, the dot diameter data at the same dot position as the print data is input from the ROM 2 to the latch 21. Similarly, when print data for three adjacent dots is input to the latches 18 to 20, dot diameter data at the same dot position as the print data for the three dots is simultaneously input to the latches 21 to 23. At this time, the dot of interest is a dot of print data input to the latch 19.
[0046]
The AND gate groups 37 to 40 supply an AND between the output of the latch circuit 18 and the output of the latch circuit 21 to the adder 49a. The AND gate groups 41 to 44 supply an AND between the output of the latch circuit 19 and the output of the latch circuit 22 to the adder 49a. The AND gate groups 45 to 48 supply the AND of the output of the latch circuit 20 and the output of the latch circuit 23 to the adder 49a. That is, each AND gate group supplies dot diameter data to the adder 49 when the print data input to the latch circuits 18 to 20 is data indicating “printing”, but indicates “no printing”. If it is data, “0” is supplied to the adder 49. The adder 49 adds the outputs of these three AND gate groups, and supplies the sum to the divider 50 as the sum of the dot diameter data.
[0047]
The output of the latch circuits 18 to 20 is also supplied to the adder 49a. The adder 49a adds these outputs to obtain the number of dots whose print data indicates “printed”, and the number of dots to be printed. To the divider 50.
[0048]
The divider 50 divides the sum of the dot diameter data supplied from the adder 49a by the number of dots to be printed supplied from the adder 49a. For example, when all the print data of 3 dots is “printed” data, the sum of the dot diameter data is divided by 3.
[0049]
The division result is supplied to the subtractor 55. The subtractor 55 is also supplied with dot diameter data of the focused dot from the AND gate groups 41 to 44, and the subtractor 55 subtracts the dot diameter data of the focused dot from the division result. The subtraction result is sent to the adder 49b and added to 08H. The addition result is supplied to the AND gate groups 51 to 54, and the addition result is output to the control circuit 26 as corrected print data only when the output of the latch 19 is "1", that is, when the target dot is printed. The
[0050]
According to the above procedure, the dot diameter data of the focused dot and its neighboring dots are read, the average value thereof is calculated, the difference from the dot diameter data of the focused dot is added to 08H, and the corrected print data of the focused dot It can be transmitted to the control circuit 26 as (gradation print data). The above procedure is repeated until the count value of the column address counter of the transmission address circuit 15 reaches a predetermined value, and the corrected data is sequentially supplied to the gradation LED head 4 as actual print data. By performing the above for all the dots in one line, it is possible to correct the MTF variation for all the dots of the LED head. The line counter 25 counts the input latch signal, and transmits a reset signal to the control circuit 26 when the count value reaches the number of lines for one page. Thus, the above operation is repeated from the first line on the next page.
[0051]
Here, the light intensity distributions of the light emitting elements of the adjacent three dots are as shown by the curves a1 to a3 in FIG. 8A, and the combined light intensity distribution is as shown by the curve b. Suppose there is. At the center dot among the three dots, the light intensity distribution is greatly distorted because the MTF value is small. At this time, the dot diameter of each dot is S8, S8 + ΔS, S8 from the left, and the dot diameter data stored in the ROM 2 is 8, 9, 8 in order from the left dot in the figure. At this time, the target dot is the center dot, and the data input to the logical operation circuit 24 are 8, 9, and 8 in order from the left dot. The average value of the correction data of these three dots is 8, and the dot diameter data 9 is subtracted from the average value 8 to obtain -1. 07H obtained by adding -1 to 08H (standard) is output to the control circuit 26 as the gradation data of the dot of interest. This data is a value smaller than the standard output value 08H, and when the correction is not performed, the dot diameter becomes large, but the difference between the adjacent dots is small due to the correction as shown in FIG. 8B. ing.
[0052]
The effects obtained by the configuration of the first embodiment will be described below with reference to FIGS. As shown in FIG. 9, the dot diameters of the first dot, the fourth dot, and the sixth dot are larger by ΔS from the average value (08), and the dot diameters of the second, third, and seventh dots are Δ from the average value. It is assumed that S is smaller and the dot diameter of the fifth dot is equal to the average value. In this case, the dot diameter data stored in the first to seventh dot ROMs are 9, 7, 7, 9, 8, 9, 7, respectively.
[0053]
As described above, the logical operation circuit 24 reads the dot diameter data of the focused dot and its adjacent dots, calculates the average value thereof, and subtracts the dot diameter data of the focused dot from the average value to 08H. And the addition result is transmitted to the control circuit 26 as the tone data of the focused dot.
[0054]
When the second to sixth dots are the dots of interest, the average values are 8, 8, 8, 9, and 8, respectively. The values obtained by subtracting the dot diameter data of the target dot from these average values are 1, 1, -1, 1, and -1. As a result of adding 8 to these values, 9, 9, 7, 9, and 7 become the print gradation data of the second to sixth dots.
[0055]
When the special dot having only one adjacent dot (for example, the first dot and the 4992th dot) is the target dot, the logical operation circuit 24 determines that the dot whose print data indicates “no printing” is the target dot. Arithmetic is performed as if they are adjacent.
[0056]
That is, in FIG. 9, when the first dot is a special dot having only one adjacent dot, the sum of the dot diameter data of three adjacent dots when the first dot is the target dot is 0 + 9 + 7 = 16. In addition, since the number of dots in which the print data indicates “printed” is 2, the average value is 16/2 = 8. The value 7 obtained by adding the standard value 8 to the value −1 obtained by subtracting the dot diameter data 9 of the target dot (first dot) from this average value is the corrected print data (tone print data) of the first dot. It becomes.
[0057]
Similarly, when the seventh dot is a special dot having only one adjacent dot, the sum of the dot diameter data of three adjacent dots when the seventh dot is the target dot is 9 + 7 + 0 = 16, and Since the number of dots indicating “printed” in the print data is 2, the average value is 16/2 = 8. A value 9 obtained by adding the standard value 8 to the value 1 obtained by subtracting the dot diameter data 7 of the target dot (seventh dot) from this average value is the corrected print data (gradation print data) of the seventh dot. Become.
[0058]
As a result, the LED head has 7, 9, 9, 7, 9, 7, 9 as the gradation print data of the first to seventh dots (actually, 7H, 9H, 9H, 7H, 9H, 7H, 9H) is transmitted to the LED head.
[0059]
Here, the print data is “1” for each dot, that is, “printed”, and the division result is rounded up to an integer. As a result, as shown in FIG. 10A, conventionally, even when the light emission intensity of each light emitting element is the same, even when the dot diameter varies, the dot diameter of each dot is close to the average value by the correction. The dot diameter does not change extremely between adjacent dots, and a smooth printing result is obtained.
[0060]
Modification of the first embodiment.
In the first embodiment, it is assumed that the light intensity distribution of each light emitting element is affected by the adjacent light emitting elements, but depending on the characteristics of the lens used (especially when the MTF value is low), In some cases, the light intensity distribution of the light-emitting elements is affected not only by adjacent light-emitting elements but also by more light-emitting elements.
[0061]
Hereinafter, a case where the light intensity distribution of the light emitting element is as shown in FIGS. 11 and 12 will be considered. 11 and 12 show light intensity distributions of light emitting elements respectively corresponding to a target dot (center dot), adjacent dots adjacent to the target dot, and dots adjacent to the adjacent dots (hereinafter referred to as adjacent dots). A solid line) and a combined light intensity distribution (one-dot chain line) of a total of five light emitting elements are shown. FIG. 12 shows a case where there is no variation in the MTF of each lens and the light quantity distribution after passing through the lens is uniform. FIG. 11 shows that the MTF of the lens varies and the light quantity distribution after passing through the lens is uniform. This is a case where the lens MTF of the target dot is not high (when the MTF of the lens at the target dot is higher than the lens of other dots).
[0062]
FIG. 13 shows the light intensity distribution when the adjacent light emitting element does not emit light in the case of FIG. 11 and only the light emitting element corresponding to the dot of interest and the adjacent dot emits light, and FIG. 14 shows the case of FIG. 2 shows the light intensity distribution when only the light emitting elements corresponding to the target dot and the adjacent dot are caused to emit light without causing the adjacent light emitting element to emit light. From these figures, it can be seen that the light intensity distribution of the light emitting element of the target dot is influenced by the light emission of the adjacent light emitting elements.
[0063]
The modification of the first embodiment makes it possible to correct the dot diameter including the influence of adjacent elements. Therefore, in this modified example, the dot diameter of each light emitting element is measured and the dot diameter data is stored in the ROM in the same manner as in the first embodiment. And the same calculation is performed to give to the dot of interest. Accordingly, the same correction effect can be obtained even when each light emitting element is affected by the adjacent element.
[0064]
Embodiment 2. FIG.
The configuration of Embodiment 2 of the image recording apparatus of the present invention is shown in FIG. The second embodiment has the same configuration as that of the first embodiment shown in FIG. 1, but the video signal and print data output from the print control unit to the print data correction circuit are not binary data but multi-value data. This is different from the first embodiment.
[0065]
As shown in FIG. 15, the apparatus according to the second embodiment includes a print control unit 1, a print data correction circuit 3 </ b> A, a gradation LED head 4, and a non-volatile storage element (for example, EEPROM) ROM 2. The print control unit 1 outputs a video signal including print data and a control signal for controlling the operation of the print data correction circuit 3A to the print data correction circuit 3A. In addition, a timing signal for synchronizing the print control unit 1 and the print data correction circuit 3A is output from the print data correction circuit 3A to the print control unit 1. Corrected print data output from the print data correction circuit 3A to the gradation LED head 4 in synchronization with the timing signal, a latch signal for holding the corrected print data in the LED head 4, and a clock signal are output. Is done. The ROM 2 connected to the print data correction circuit 3A is for storing dot correction data based on the measurement results for each dot of the spot diameter on the imaging surface of the gradation LED head 4.
[0066]
Next, the configuration of the print data correction circuit 3A will be described with reference to FIG. The print data correction circuit 3A used in the second embodiment has the same configuration as that of the print data correction circuit 3 shown in FIG. 2, but includes a buffer 11, a one-line reception buffer 12, latches 18 to 20, and a logical operation. Since the print data transmitted between the circuits 24A is not 1-bit data (binary data) but 4-bit data (multi-value data), they are connected to each other by four signal lines.
[0067]
Similar to the print data correction circuit 3, the print data correction circuit 3A includes a buffer 11, a one-line reception buffer 12, a selector 13, a reception address circuit 14, a transmission address circuit 15, a timing generation circuit 16, latches 18 to 23, and a logical operation circuit. 24A, dot counter 17, line counter 25, and control circuit 26 are included. The 1-line reception buffer 12 is connected to the input and output of the buffer 11 that receives the video signal from the print control unit 1 and the output of the selector 13. Two inputs of the selector 13 are connected to the output of the reception address circuit 14 and the output of the transmission address circuit 15, respectively. The buffer switching signal that is the output of the selector 13 is supplied to the buffer 11. The input of the reception address circuit 14 is connected to the output of the timing generation circuit 16, and the input of the transmission address circuit 15 is connected to the output of the dot counter 17. The timing generation circuit 16 supplies a timing signal to the print control unit 1, and the print control unit 1 supplies a control signal to the timing generation circuit 16.
[0068]
A transfer clock signal is output from the timing generation circuit 16 to the gradation LED head 4, the latches 18 to 23, and the dot counter 17. A latch signal is also output from the timing generation circuit 16 to the gradation LED head 4. The output of the latch 18 is connected to the input of the latch 19 and the input of the logic operation circuit 24A, the output of the latch 19 is connected to the input of the latch 20 and the input of the logic operation circuit 24A, and the output of the latch 20 is connected to the input of the logic operation circuit 24A. Connected to input. The buffer 11 is connected to the input of the latch 18. The output of the latch 21 is connected to the input of the latch 22 and the input of the logic operation circuit 24A, and the output of the latch 22 is connected to the input of the latch 23 and the input of the logic operation circuit 24A. The output of the latch 23 is connected to the input of the logic operation circuit 24A.
[0069]
The ROM 2 is connected to the input of the latch 21 and the output of the dot counter 17 respectively. The data lines from the ROM 2 through the latches 21 to 23 to the logic operation circuit 24A are composed of four signal lines so that 4-bit parallel dot diameter data can be transmitted. The control circuit 26 is connected to the output of the raster line counter 25, the output of the logic operation circuit 24A, and the input of the gradation LED head 4. The data line from the logic operation circuit 24A through the control circuit 26 to the gradation LED head 4 is composed of four signal lines so that 4-bit parallel print data can be transmitted. A latch signal is supplied to the line counter 25 so that the number of lines for one page can be counted.
[0070]
FIG. 17 shows the configuration of the logical operation circuit 24A. As shown in the figure, the logical operation circuit 24A includes AND gates 37 to 48, an adder 49, a divider 50, a subtractor 55, an adder 56, AND gates 51 to 54, and OR gates 57 to 59.
[0071]
The AND gates 37 to 40 are supplied with the 4-bit print data output from the latch 18 via the OR gate 57 and the 4-bit dot diameter data output from the latch 21. The AND gates 41 to 44 are supplied with the 4-bit print data output from the latch 19 via the OR gate 58 and the 4-bit dot diameter data output from the latch 22.
The AND gates 45 to 48 are supplied with the 4-bit print data output from the latch 20 via the OR gate 59 and the 4-bit dot diameter data output from the latch 23.
[0072]
The outputs of the AND gates 37 to 40, the outputs of the AND gates 41 to 44, and the outputs of the AND gates 45 to 48 are supplied to the adder 49. The outputs of the OR gates 57 to 59 are supplied to the adder 49. The adder 49 supplies the 4-bit dot diameter data and 2-bit dot number data as the addition result to the divider 50. The divider 50 divides the addition result by the dot number data, and the division result is supplied to the subtractor 55. Further, the dot diameter data stored in the latch 22 is supplied to the subtracter 55 via the AND gates 41 to 44, and the subtracter 55 receives the dot diameter supplied from the AND gates 41 to 44 from the division result of the divider 50. Subtract data. The adder 56 is supplied with the 4-bit subtraction result of the subtractor 55 and the 4-bit print data (gradation data) output from the latch 19. The adder 56 adds the subtraction result of the subtractor 55 and the print data (gradation data) output from the latch 19. The 4-bit addition result of the adder 56 is supplied to AND gates 51 to 54. The outputs of the AND gates 51 to 54 are supplied to the control circuit 26 as print gradation data.
[0073]
Next, the operation of the second embodiment having the above configuration will be described. In FIG. 15, when the print preparation is completed, the print control unit 1 transmits a timing signal to an upper controller (not shown), and receives a 4-bit video signal edited for each page by the upper controller. This video signal is sent together with the control signal from the print controller 1 to the print data correction circuit 3A. The print data correction circuit 3A shown in FIG. 16 performs the following processing on this video signal. That is, the timing generation circuit 16 that has received the control signal generates a reception clock signal and sends it to the reception address circuit 14. The video signal received by the buffer 11 is stored at an address in the one-line reception buffer 12 designated by the reception address circuit 14 in synchronization with the reception clock signal. The video signal is stored in the one-line reception buffer 12 every time a video signal for one line is received from the print control unit 1.
[0074]
When the transmission address circuit 15 designates an address in the one-line reception buffer 12, the data at that address is latched in the latches 18 to 20, and is supplied to the logic operation circuit 24 as three consecutive columns of data. Until all the data in the one-line reception buffer is latched, the dot counter 17 increments a count value indicating what number of dot the data is. The dot counter 17 also transmits to the ROM 2 the address where the dot diameter data input to the logic operation circuit 24A is stored. Thereby, at the same time as data is input to the logical operation circuit 24A, the dot diameter data of the data is input from the ROM 2.
[0075]
In the logical operation circuit 24A, corrected print data consisting of 4 bits per dot for the center dot of the input 3 columns of data from the input 4 columns of 3 columns and 4 bits of dot diameter data. Is calculated.
[0076]
Here, the dot diameter data stored in the ROM 2 is the same as that in the first embodiment. That is, also in the second embodiment, the dot diameter on the imaging surface of the LED head 4 is measured for all the light emitting elements of the LED head 4 by the same procedure as that described with reference to FIG. Calculate it. As described with reference to FIG. 3, by changing the gradation data supplied to the LED head 4, the dot density, that is, the dot diameter can be changed in dot units. Further, the gradation data and the dot diameter are in a proportional relationship. Therefore, the dot diameter of the dots when data of 08H (center value) is transmitted to the gradation LED head and printed is set to be the average value of the measured dot diameters. The dot diameter at this time is S8.
[0077]
If the change in the dot diameter when the gradation data is changed by one step from 08H to 09H by 01H is ΔS, the dot diameter when each gradation data in the range of 01H to 0FH is changed by one step is shown. The change is also almost ΔS. Therefore, a dot whose dot diameter is larger than the average value by ΔS gives dot diameter data of 8 + 1 = 9. Further, dot diameter data of 8−2 = 6 is given to dots whose dot diameter is smaller by 2ΔS than the average value. When the data is given as described above, the gradation data and the dot diameter data have a relationship as shown in FIG. Using this relationship, the measured dot diameter data is converted into 4-bit gradation data, and the converted gradation data is stored in the ROM 2 as dot diameter data for each dot.
[0078]
Next, the operation of the logic operation circuit 24A will be described in detail. In FIG. 17, simultaneously with the input of 4-bit print data to the latch 18, the dot diameter data at the same dot position as the print data is input from the ROM 2 to the latch 21. Similarly, when print data for three adjacent dots is input to the latches 18 to 20, dot diameter data at the same dot position as the print data for the three dots is simultaneously input to the latches 21 to 23. At this time, the dot of interest is a dot of print data input to the latch 19.
[0079]
The AND gate groups 37 to 40 supply the adder 49 with the AND of the output of the latch 18 and the output of the latch circuit 21 supplied via the OR gate 57. The AND gate groups 41 to 44 supply the adder 49 with the AND of the output of the latch 19 and the output of the latch circuit 22 supplied via the OR gate 58. The AND gate groups 45 to 48 supply the adder 49 with the AND of the output of the latch 20 and the output of the latch circuit 23 supplied via the OR gate 59.
[0080]
That is, each AND gate group supplies dot diameter data to the adder 49 when the print data input to the latch circuits 18 to 20 is data indicating “printing”, but indicates “no printing”. If it is data, “0” is supplied to the adder 49. The adder 49 adds the outputs of these three AND gate groups, and supplies the sum to the divider 50 as the sum of the dot diameter data.
[0081]
The outputs of the OR gates 57 to 59 are also supplied to the adder 49, and the adder 49 adds these outputs to obtain the number of dots whose print data indicates “printed” and print it. This is supplied to the divider 50 as the number of dots.
[0082]
The divider 50 divides the sum of the dot diameter data supplied from the adder 49 by the number of dots to be printed supplied from the adder 49. For example, when all the print data of 3 dots is data indicating “printed”, the sum of the dot diameter data is divided by 3. The division result is input to the subtractor 55, and the dot diameter data of the target dot supplied via the AND gate groups 41 to 44 is subtracted from the division result. Next, the subtraction result is input to the adder 56 and added to the print data (tone data) of the target dot supplied from the latch 19. The addition result of the adder 56 is input to the AND gate groups 51 to 54, and the addition result is controlled as print gradation data only when the output of the OR gate 58 is "1", that is, when the dot of interest is printed. It is output to the circuit 26.
[0083]
The above procedure reads the dot diameter data of the target dot and its neighboring dots, calculates the average value, and adds the difference from the dot diameter data of the target dot to the tone dot data of the target dot. The gradation print data can be transmitted to the control circuit 26. The above procedure is repeated until the count value of the column address counter of the transmission address circuit 15 reaches a predetermined value, and the corrected data is sequentially supplied to the gradation LED head 4 as actual print data. By performing the above for all the dots in one line, it is possible to correct the MTF variation for all the dots of the LED head. Also in the second embodiment, as in the first embodiment, when the special dot having only one adjacent dot (for example, the first dot and the 4992th dot) is the target dot, the logic operation circuit 24A displays the print data “ The calculation is performed assuming that the dot indicating “no printing” is adjacent to the dot of interest. The line counter 25 counts the input latch signal, and transmits a reset signal to the control circuit 26 when the count value reaches the number of lines for one page. Thus, the above operation is repeated from the first line on the next page.
[0084]
Here, the light intensity distributions of the light emitting elements of the adjacent three dots are as shown by the curves a1 to a3 in FIG. 19A, and the combined light intensity distribution is as shown by the curve b. Suppose there is. In the center dot among the three dots, the light intensity distribution is greatly distorted because the MTF value is large. If the gradation data before correction of the target dot (center dot) is 08H, and the dot diameter data stored in the ROM 2 are 8, 10, 8 in order from the left dot in the figure, logical operation The correction data input to the circuit 24A are 8, 10, and 8 in order from the left dot. The average value of these three dot diameter data is 9, and the difference between this data and the dot diameter data of the target dot is calculated. Next, a result obtained by adding the calculation result and the gradation data of the target dot, that is, 08H + (− 01H) = 07H is output to the control circuit 26. This data has a smaller value than the original gradation data of the target dot, and when correction is not performed, the dot diameter larger than that of the adjacent dot is corrected with the adjacent dot as shown in FIG. The difference is small.
[0085]
Even in the second embodiment, as in the first embodiment, the dot diameter of each dot is close to the average value even when the dot diameter varies even if the light emission intensity of each light emitting element is the same as the conventional one. The dot diameter does not change extremely between adjacent dots, and a smooth gradation image can be obtained.
[0086]
Further, in a small isolated region (for example, a region having a constitutional dot number of 3 × 3 dots or less), the adhesion force of the toner is low, so that the dot diameter when the toner image is formed is small, but according to the above embodiment. In other words, since the average of the surrounding dot diameters is taken, there is an effect that the dot diameter of the isolated region is prevented from being reduced.
[0087]
Embodiment 3 FIG.
When considering a pattern to be printed over a wide range, in the above embodiment, the MTF variation of the lens can be suppressed when looking at a certain part of the pattern, but there is a drawback that the variation remains when viewed as a whole pattern. Therefore, in the third embodiment, when the print data is binary, the dot diameters of all dots printed in the pattern of a certain area are corrected together so that the MTF variation of the lens array can be suppressed. ing.
[0088]
FIG. 20 shows the configuration of Embodiment 3 of the image recording apparatus of the present invention. As shown in the figure, this apparatus includes a print control unit 1, a print data correction circuit 3 </ b> B, a gradation LED head 4, and a nonvolatile storage element (e.g., EEPROM) ROM 2. The print controller 1 outputs a video signal including print data and a control signal for controlling the operation of the print data correction circuit 3B to the print data correction circuit 3B. In addition, a timing signal for synchronizing the print control unit 1 and the print data correction circuit 3B is output from the print data correction circuit 3B to the print control unit 1. Corrected print data output from the print data correction circuit 3B to the gradation LED head 4 in synchronization with the timing signal, a latch signal for holding the corrected print data in the LED head 4, and a clock signal are output. Is done. The ROM 2 connected to the print data correction circuit 3B is for storing dot diameter data based on the measurement result of each spot diameter dot on the imaging surface of the gradation LED head 4.
[0089]
Next, the configuration of the print data correction circuit 3B will be described with reference to FIG. As shown in the figure, the print data correction circuit 3B includes a buffer 11, a one-line reception buffer 12, a selector 13, a reception address circuit 14, a transmission address circuit 15, a timing generation circuit 16, latches 18 and 21, a shift register 60, A logic operation circuit 24B, a dot counter 17, a line counter 25, and a control circuit 26 are included. The 1-line reception buffer 12 is connected to the input and output of the buffer 11 that receives the video signal from the print control unit 1 and the output of the selector 13. Two inputs of the selector 13 are connected to the output of the reception address circuit 14 and the output of the transmission address circuit 15, respectively. The buffer switching signal that is the output of the selector 13 is supplied to the buffer 11. The input of the reception address circuit 14 is connected to the output of the timing generation circuit 16, and the input of the transmission address circuit 15 is connected to the output of the dot counter 17. The timing generation circuit 16 supplies a timing signal to the print control unit 1, and the print control unit 1 supplies a control signal to the timing generation circuit 16.
[0090]
A transfer clock signal is output from the timing generation circuit 16 to the gradation LED head 4, the latches 18 and 21, and the dot counter 17. A latch signal is also output from the timing generation circuit 16 to the gradation LED head 4. The output of the latch 18 is connected to the clock input terminal of the shift register 60 and the input of the logic operation circuit 24B, and the output of the shift register 60 is connected to the input of the logic operation circuit 24B. The buffer 11 is connected to the input of the latch 18. The output of the latch 21 is connected to the input of the logic operation circuit 24B. The ROM 2 is connected to the input of the latch 21, the input of the shift register 60, and the output of the dot counter 17, respectively. Data lines from the ROM 2 through the latch 21 and the shift register 60 to the logical operation circuit 24B are each composed of four signal lines so that 4-bit parallel dot diameter data can be transmitted. The control circuit 26 is connected to the output of the raster line counter 25, the output of the logic operation circuit 24B, and the input of the gradation LED head 4. The data line from the logic operation circuit 24B to the gradation LED head 4 via the control circuit 26 is composed of four signal lines so that 4-bit parallel print data can be transmitted. A latch signal is supplied to the line counter 25 so that the number of lines for one page can be counted.
[0091]
FIG. 22 shows the configuration of the logical operation circuit 24B. As shown in the figure, the logical operation circuit 24B includes AND gates 37 to 44, a logical operation unit 61, and AND gates 51 to 54.
[0092]
The AND gates 37 to 40 are supplied with print data from the latch 18 and 4-bit dot diameter data from the latch 21. The AND gates 41 to 44 are supplied with 4-bit dot diameter data from the shift register 60 and print data from the latch 18. The outputs of the AND gates 37 to 40 and the outputs of the AND gates 41 to 44 are supplied to the logical operation unit 61. The AND gates 51 to 54 are supplied with the output of the logic unit 61 and the print data from the latch 18. Outputs of the AND gates 51 to 54 are supplied to the control circuit 26 as print data.
[0093]
Hereinafter, the operation of the third embodiment having the above configuration will be described in detail with reference to the drawings. In FIG. 20, when printing preparation is completed, the print control unit 1 transmits a timing signal to a host controller (not shown) and receives a video signal edited for each page by the host controller. This video signal is sent together with the control signal from the print control unit 1 to the print data correction circuit 3B. The print data correction circuit 3B shown in FIG. 21 performs the following processing on this video signal. That is, the timing generation circuit 16 that has received the control signal generates a reception clock signal and sends it to the reception address circuit 14. The video signal received by the buffer 11 is stored at an address in the one-line reception buffer 12 designated by the reception address circuit 14 in synchronization with the reception clock signal. The video signal is stored in the one-line reception buffer 12 every time a video signal for one line is received from the print control unit 1.
[0094]
When the transmission address circuit 15 designates a column address in the one-line reception buffer 12, the data at that address is latched in the latch circuit 18. The data of the latch 18 is input to the logic operation circuit 24B. Until all the data in the 1-line reception buffer 12 is latched, the dot counter 17 increments a count value indicating what number of dots the data to be latched is. The dot counter 17 also sends to the ROM 2 the address where the dot diameter data input to the logical operation circuit 24B is stored. As a result, at the same time as data is input to the logical operation circuit 24, the dot diameter data is input from the ROM 2 via the latch 21. In the logical operation circuit 24B, from the 1-bit print data input from the latch 18 and the 4-bit dot diameter data respectively input from the latch 21 and the shift register 60, 4 bits per dot for the dot of the print data. The corrected print data consisting of is calculated.
[0095]
Here, data stored in the ROM 2 will be described. Also in the third embodiment, the dot diameter on the imaging surface of the LED head 4 is measured for all the light emitting elements of the LED head 4 by the same procedure as described with reference to FIG. Keep it. As described with reference to FIG. 4, by changing the gradation data supplied to the LED head 4, the dot density, that is, the dot diameter can be changed in dot units. Further, the gradation data and the dot diameter are in a proportional relationship. Therefore, the dot diameter of the dot when data of 08H (center value) is transmitted to the gradation LED head and printed is set to be the average value of the measured dot diameter. The dot diameter at this time is S8.
[0096]
If the change in dot diameter when the gradation data is changed by one step from 08H to 09H by 01H is ΔS, each dot diameter when each gradation data in the range from 01H to 0FH is changed by one step. The amount of change is substantially ΔS. Therefore, a dot whose dot diameter is larger by ΔS than the average value gives dot diameter data of 08H-01H = 07H. Further, dot diameter data of 08H + 02H = 0AH is given to a dot whose dot diameter is smaller by 2ΔS than the average value. When the data is given as described above, the gradation data and the dot diameter data have a relationship as shown in FIG. Using this relationship, the measured dot diameter data is converted into 4-bit gradation data, and the converted gradation data is stored in the ROM 2 as dot diameter data for each dot.
[0097]
Next, the operation of the logic operation circuit 24B will be described in detail. In FIG. 22, simultaneously with the print data being input to the latch 18, the dot diameter data at the same dot position as the print data is input from the ROM 2 to the latch 21. The shift register 60 holds the dot diameter data of the dot number input first among the continuous print data “1”. The logical calculator 61 receives the dot diameter data held in the shift register 60 and the dot diameter data of the dot of interest.
[0098]
Here, it is assumed that the input print data is dot number (N-1) data, and the data is "0". At this time, the output of the latch 18 is “0”, so the outputs of the AND gates 51 to 54 are “0”, and this dot is not printed. Next, consider a case where print data “1” (dot number N) is input to the latch 18. At this time, the output of the latch 18 is “1”, and the dot diameter data of the dot number N is output from the latch 21. At the same time, since the output “1” of the latch 18 is input to the clock input terminal of the shift register 60, the dot diameter data of the dot number N is supplied from the shift register 60 to the logical operation unit 61 via the AND gates 41 to 44. At this time, since the outputs of the AND gates 37 to 40 are also supplied to the logical operation unit 61, the dot diameter data of the dot number N is supplied to the logical operation unit 61 from both the AND gates 37 to 40 and the AND gates 41 to 44. Will be.
[0099]
If the print data of the next dot (dot number N + 1) is also “1”, the dot diameter data of dot number N + 1 is output from the latch 21, but the output of the latch 18 does not change and is “1”. The output of the shift register 60 still retains the dot diameter data of the dot number N. For this reason, the dot diameter data of the dot number N and the dot diameter data of the dot number N + 1 are input to the logic unit 61.
[0100]
If the print data of the next dot (dot number N + 2) is also “1”, the dot diameter data of dot number N + 2 is output from the latch 21, but the output of the latch 18 does not change and is “1”. Therefore, the dot diameter data of the dot number N is held in the output of the shift register 60. Accordingly, the dot diameter data of the dot number N and the dot diameter data of the dot number N + 2 are input to the logic unit 61.
[0101]
As described above, the shift register 60 uses the dot diameter data at the dot position when the print data output from the latch 18 changes from “0” to “1”, and the print data output from the latch 18 next. Is held until becomes "0". Thus, the retained dot diameter data can be compared with the dot diameter data of a series of dots connected to the dot, and the dot diameter can be corrected according to the difference. It becomes possible to align the dot diameter of the dot cluster with the dot diameter of the dot at the end.
[0102]
Next, the operation of the logic unit 61 will be specifically described. As described above, the dot diameter data of the dot located at the end of a series of dot groups to be printed, which is held in the shift register 60, is input to the logical operation unit 61. This is DATA1. At the same time, the dot diameter data of the dot of interest is input to the logic unit 61. This is DATA2. For the above two input data, the logical operation unit 61
DATA = 08H + (DATAl-DATA2)
Perform the operation.
[0103]
In other words, the logical operation unit 61 obtains a difference between the reference dot diameter data (DATA1) and the dot diameter data (DATA2) at the currently focused dot position, and corrects the dot diameter of the focused dot by the difference. . The result is output to the control circuit 26 as gradation print data of the target dot. With the above processing, when printing a group of print dots, the dot diameter of other dots can be made closer to the dot diameter of the dot located at the end, and the variation of the MTF of the lens is compensated, so that The dot diameter can be made uniform. The line counter 25 counts the input latch signal, and transmits a reset signal to the control circuit 26 when the count value reaches the number of lines for one page. Thus, the above operation is repeated from the first line on the next page.
[0104]
Here, the light intensity distributions of the light emitting elements of the adjacent three dots are as shown by the curves a1 to a3 in FIG. 24A, and the combined light intensity distribution is as shown by the curve b. Suppose there is. At this time, it is assumed that the dot diameter data held in the shift register 60 is 8, and the dot diameter data of the focused dot (dot in the center of the figure) is 10. In this case, the correction data input to the logical operator 24B is 8, 10, and the logical operator 61 calculates 8-10 = −2. For this reason, the gradation print data of the dot of interest is 08H-02H = 06H, and exposure is performed with energy smaller than the standard, so that the dot diameter of the dot printed at the end approaches. Therefore, the dots that become larger if not corrected have the same dot diameter as the dots on both sides as shown in FIG.
[0105]
Also in the third embodiment, as in the first and second embodiments, the dot diameter of each dot is close to the average value even when the dot diameter varies even if the light emission intensity of each light emitting element is the same. Furthermore, the dot diameter does not change extremely between adjacent dots, and a smooth printing result can be obtained.
[0106]
In the third embodiment, in addition to this, when there is a series of dots to be printed, the dot diameter data of the dots located at the ends is held, and the dot diameter data of each series of dots is sequentially compared and corrected. Is transmitted to the gradation LED head as the print gradation data of the dot of interest, so that the dot diameters of a group of dots can be made equal to the dot diameters at the ends, so that a uniform image can be obtained.
[0107]
Embodiment 4 FIG.
In the third embodiment, the input print data (video signal) is binary data, but in the fourth embodiment, the input print data is multi-value data, and a gradation image can be formed. .
[0108]
FIG. 25 shows the configuration of Embodiment 4 of the image recording apparatus of the present invention. As shown in the figure, the apparatus includes a print control unit 1, a print data correction circuit 3 </ b> C, a gradation LED head 4, and a nonvolatile storage element (e.g., EEPROM) ROM 2. The print control unit 1 outputs a video signal including print data and a control signal for controlling the operation of the print data correction circuit 3C to the print data correction circuit 3C. A timing signal for synchronizing the print control unit 1 and the print data correction circuit 3C is output from the print data correction circuit 3C to the print control unit 1. Corrected print data output from the print data correction circuit 3C to the gradation LED head 4 in synchronization with the timing signal, a latch signal for holding the corrected print data in the LED head 4, and a clock signal are output. Is done. The ROM 2 connected to the print data correction circuit 3C is for storing correction data based on the measurement result for each dot of the spot diameter on the imaging surface of the gradation LED head 4.
[0109]
Next, the configuration of the print data correction circuit 3C will be described with reference to FIG. The print data correction circuit 3C used in the fourth embodiment has the same configuration as the print data correction circuit 3B shown in FIG. 21, but the buffer 11, the one-line reception buffer 12, the latch 18, and the logic operation circuit 24C. Since the print data transmitted between them is not 1-bit data (binary data) but 4-bit data (multi-value data), they are connected to each other by four signal lines.
[0110]
As shown in FIG. 26, the print data correction circuit 3C includes a buffer 11, a one-line reception buffer 12, a selector 13, a reception address circuit 14, a transmission address circuit 15, a timing generation circuit 16, latches 18 and 21, a shift register 60, An OR gate 62, a logic operation circuit 24C, a dot counter 17, a line counter 25, and a control circuit 26 are included. The 1-line reception buffer 12 is connected to the input and output of the buffer 11 that receives the video signal from the print control unit 1 and the output of the selector 13. Two inputs of the selector 13 are connected to the output of the reception address circuit 14 and the output of the transmission address circuit 15, respectively. The buffer switching signal that is the output of the selector 13 is supplied to the buffer 11. The input of the reception address circuit 14 is connected to the output of the timing generation circuit 16, and the input of the transmission address circuit 15 is connected to the output of the dot counter 17. The timing generation circuit 16 supplies a timing signal to the print control unit 1, and the print control unit 1 supplies a control signal to the timing generation circuit 16.
[0111]
A transfer clock signal is output from the timing generation circuit 16 to the gradation LED head 4, the latches 18 and 21, and the dot counter 17. A latch signal is also output from the timing generation circuit 16 to the gradation LED head 4. The output of the latch 18 is connected to the input of the logic operation circuit 24C and the input of the OR gate 62. The output of the OR gate 62 is connected to the clock input terminal of the shift register 60. The buffer 11 is connected to the input of the latch 18. The output of the latch 21 is connected to the input of the logic operation circuit 24C. The ROM 2 is connected to the input of the latch 21, the input of the shift register 60, and the output of the dot counter 17, respectively. Data lines from the ROM 2 through the latch 21 and the shift register 60 to the logical operation circuit 24C are each composed of four signal lines so that 4-bit parallel dot diameter data can be transmitted. The control circuit 26 is connected to the output of the raster line counter 25, the output of the logic operation circuit 24C, and the input of the gradation LED head 4. The data line from the logic operation circuit 24C through the control circuit 26 to the gradation LED head 4 is composed of four signal lines so that 4-bit parallel print data can be transmitted. A latch signal is supplied to the line counter 25 so that the number of lines for one page can be counted.
[0112]
FIG. 27 shows the configuration of the logical operation circuit 24C. As shown in the figure, the logical operation circuit 24C includes AND gates 37 to 44, a logical operation unit 61, AND gates 51 to 54, and an OR gate 57.
[0113]
4-bit print data is input from the latch 18 via the OR gate 57 to the AND gates 37 to 40, and simultaneously 4-bit dot diameter data is input from the latch 21. The AND gates 41 to 44 receive dot diameter data from the shift register 60 and simultaneously input 4-bit print data from the latch 18 via the OR gate 57. The outputs of the AND gates 37 to 40 and the outputs of the AND gates 41 to 44 are supplied to the logical operation unit 61. The AND gates 51 to 54 receive the output of the logical operation unit 61, and simultaneously, 4-bit print data is input from the latch 18 via the OR gate 57. Outputs of the AND gates 51 to 54 are supplied to the control circuit 26 as print data.
[0114]
The operation of the fourth embodiment having the above configuration will be described below. In FIG. 25, when printing preparation is completed, the print control unit 1 transmits a timing signal to a host controller (not shown) and receives a video signal edited for each page by the host controller. The video signal is sent from the print control unit 1 to the print data correction circuit 3C together with the control signal. The print data correction circuit 3C shown in FIG. 26 performs the following processing on this video signal. That is, the timing generation circuit 16 that has received the control signal generates a reception clock signal and sends it to the reception address circuit 14. The video signal received by the buffer 11 is stored at an address in the one-line reception buffer 12 designated by the reception address circuit 14 in synchronization with the reception clock signal. The video signal is stored in the one-line reception buffer 12 every time a video signal for one line is received from the print control unit 1.
[0115]
When the transmission address circuit 15 designates a column address in the one-line reception buffer 12, the data at that address is latched in the latch 18. The data of the latch 18 is input to the logic operation circuit 24C. Until all the data in the 1-line reception buffer 12 is latched, the dot counter 17 increments a count value indicating what number of dots the data to be latched is. The dot counter 17 also sends to the ROM 2 the address where the dot diameter data input to the logical operation circuit 24C is stored. As a result, the data is input to the logical operation circuit 24C, and at the same time, the dot diameter data is input from the ROM 2 via the latch 21. The logical operation circuit 24C uses the 4-bit print data input from the latch 18 and the 4-bit dot diameter data respectively input from the latch 21 and the shift register 60 to generate 4 bits per dot for the print data dot. The corrected print data consisting of is calculated.
[0116]
Here, data stored in the ROM 2 will be described. Also in the fourth embodiment, the dot diameter on the imaging surface of the LED head 4 is measured for all the light emitting elements of the LED head 4 by the same procedure as described with reference to FIG. 6, and the average value is calculated. Keep it. As described with reference to FIG. 4, by changing the gradation data of the gradation LED head 4, the dot density, that is, the dot diameter can be changed in units of dots. Further, the gradation data and the dot diameter are in a proportional relationship. Therefore, the dot diameter of the dot when data of 08H (center value) is transmitted to the gradation LED head and printed is set to be the average value of the measured dot diameter. The dot diameter at this time is S8.
[0117]
If the change in the dot diameter when the gradation data is changed by one step from 08H to 09H by 01H is ΔS, the dot diameter when each gradation data in the range of 01H to 0FH is changed by one step is shown. The change is also almost ΔS. Therefore, a dot whose diameter is larger by ΔS than the average value gives dot diameter data of -1. Further, dot diameter data of +2 is given to dots whose dot diameter is smaller by 2ΔS than the average value. When the data is given as described above, the gradation data and the dot diameter data have a relationship as shown in FIG. Data of each dot diameter measured using this relationship is converted into gradation data consisting of 4 bits, and the converted gradation data is stored in the ROM 2 as dot diameter data of each dot.
[0118]
Next, the operation of the logical operation unit 61 will be specifically described. As described above, at the same time when print data is input to the latch 18, dot diameter data at the same dot position as the print data is input from the ROM 2 to the latch 21 and the shift register 60. The shift register 60 holds the dot diameter data of the dot number input first among the continuous print data “1”. The logical operation unit 61 is input with dot diameter data (DATA1) held by the shift register 60 and dot diameter data (DATA2) of the currently focused dot. For these two input data, the logical operator 61
DATA = DATAQ + (DATA1 + DATA2)
Perform the operation.
[0119]
However, DATAQ is the gradation print data of the target dot before the dot diameter correction. That is, the logical operation unit 61 calculates the sum of the reference dot diameter data (DATA1) and the dot diameter data (DATA2) of the dot position of interest, and corrects the dot position of interest. The result is added to the previous gradation print data, and the addition result DATA is output to the control circuit 26 as gradation print data of the dot of interest.
[0120]
Here, it is assumed that the input print data is dot number (N-1) data, and the data is "0". At this time, the output of the latch 18 is “0”, so the outputs of the AND gates 51 to 54 are “0”, and this dot is not printed. Next, consider a case where print data “1” (dot number N) is input to the latch 18. At this time, the output of the latch 18 is “1”, and the dot diameter data of the dot number N is output from the latch 21. At the same time, since “1” is input from the latch 18 to the clock input terminal of the shift register 60, the dot diameter data of the dot number N is supplied from the shift register 60 to the logical operation unit 61 via the AND gates 41 to 44. At this time, since the outputs of the AND gates 37 to 40 are also supplied to the logical operation unit 61, the dot correction data of the dot number N is input to the logical operation unit 61 from both the AND gates 37 to 40 and the AND gates 41 to 44. Will be.
[0121]
If the print data of the next dot (dot number N + 1) is also “1”, the dot diameter data of dot number N + 1 is output from the latch 21, but the output of the latch 18 does not change and is “1”. In the shift register 60, the dot diameter data of the dot number N is held. For this reason, the dot diameter data of the dot number N and the dot diameter data of the dot number N + 1 are input to the logic unit 61.
[0122]
If the print data of the next dot (dot number N + 2) is also “1”, the dot diameter data of dot number N + 2 is output from the latch 21, but the output of the latch 18 does not change and is “1”. The dot diameter data of the dot number N is still held in the shift register 60. Accordingly, the dot diameter data of the dot number N and the dot diameter data of the dot number N + 2 are input to the logic unit 61.
[0123]
As described above, the shift register 60 uses the dot diameter data at the dot position when the print data output from the latch 18 changes from “0” to “1”, and the print data output from the latch 18 next. Is held until becomes "0". This makes it possible to compare the retained dot diameter data with the dot diameter data of a series of dots that are printed connected to the dot at the dot position, and correct the dot diameter according to the difference. Thus, the dot diameter of a series of dot groups can be made equal to the dot diameter of the dot located at the end thereof. The line counter 25 counts the input latch signal, and transmits a reset signal to the control circuit 26 when the count value reaches the number of lines for one page. Thus, the above operation is repeated from the first line on the next page.
[0124]
Here, the light intensity distributions of the light emitting elements of the adjacent three dots are as shown by the curves a1 to a3 in FIG. 29A, and the combined light intensity distribution is as shown by the curve b. Suppose there is. At the center dot among the three dots, the light intensity distribution is greatly distorted because the MTF value is large.
[0125]
At this time, the gradation print data of the focused dot is 08H, the dot diameter data held in the shift register 60 is 0, and the dot diameter data of the focused dot (center dot in the figure) is −2. Suppose. In this case, the correction data input to the logical operation unit 61 is 0, -2, and the logical operation unit 61 calculates 0 + (− 2) = − 2. For this reason, the gradation print data of the dot of interest is 08H-02H = 06H, and exposure is performed with energy smaller than the standard, so that the dot diameter of the dot printed at the end approaches. Accordingly, the dots that become larger without correction have the same dot diameter as the dots on both sides as shown in FIG.
[0126]
Also in the fourth embodiment, as in the first to third embodiments, the dot diameter of each dot is close to the average value even if the dot diameter varies even if the light emission intensity of each light emitting element is the same. Furthermore, the dot diameter does not change extremely between adjacent dots, and a smooth gradation image can be obtained.
[0127]
In the fourth embodiment, in addition to this, when there is a series of dots to be printed, the dot diameter data of the dots located at the ends is held, and the dot diameter data of each series of dots is sequentially compared and corrected, and the result Is transmitted to the gradation LED head as the print gradation data of the dot of interest, so that the dot diameters of a group of dots can be aligned with the dot diameters at the ends, and a uniform image can be obtained.
[0128]
In addition, when expressing a gradation in units of one dot using a gradation LED head, in order to express an intermediate gradation, for example, energy that is half of the energy that gives the maximum area (maximum dot diameter) is given. In the case of forming dots, this is the case where small dots with half the dot diameter are used to represent halftones over a wide range, such as the background of a photograph. At this time, the MTF of the lens varies. As a result, the density varies and the print quality deteriorates. In the fourth embodiment, even when dots having a small area are used over a wide range, the dot diameter in the pattern can be made uniform, and the halftone density can be kept constant. As described above, according to the fourth embodiment, even when the gradation is expressed by one dot, the density unevenness can be suppressed even if the dot is reduced, so that the print quality can be improved.
[0129]
As described above, the example in which the present invention is applied to an electrophotographic printer using LEDs has been described. However, the present invention is not limited thereto, and a thermal printer having a row of heating resistors and a display device having a row of display elements. The present invention can be applied to any device having a row of non-driven elements that are selectively driven.
[0130]
【The invention's effect】
According to the present invention, there is provided an image recording apparatus capable of forming a high-quality image in which variation in dot diameter due to the influence of adjacent or nearby light emitting elements is suppressed.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of an image recording apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a print data correction circuit according to the first embodiment.
3 is a circuit diagram showing a configuration of a logical operation circuit in the print data correction circuit of FIG. 2; FIG.
4 is a graph showing the relationship between the exposure energy amount, print density, and gradation data in the first embodiment. FIG.
FIG. 5 is a graph showing the relationship between the photosensitive drum surface potential and the dot area of a toner image.
FIG. 6 is an explanatory diagram of a procedure for measuring dot diameter data.
FIG. 7 is a graph showing the relationship between gradation data and dot diameter in the first embodiment.
FIG. 8 is a diagram illustrating the effect of dot diameter correction according to the first embodiment.
FIG. 9 is an explanatory diagram of a dot diameter correction effect according to the first embodiment.
FIG. 10 is an explanatory diagram of a dot diameter correction effect according to the first embodiment.
FIG. 11 is an explanatory diagram of a light intensity distribution of an LED light emitting element in a modification of the first embodiment.
12 is an explanatory diagram of a light intensity distribution of an LED light emitting element according to a modification of the first embodiment. FIG.
FIG. 13 is a diagram for explaining that the light intensity distribution of light emitting elements is affected by adjacent light emitting elements.
FIG. 14 is a diagram for explaining that the light intensity distribution of light emitting elements is influenced by adjacent light emitting elements.
FIG. 15 is a diagram illustrating a configuration of an image recording apparatus according to a second embodiment of the present invention.
FIG. 16 is a block diagram illustrating a configuration of a print data correction circuit according to the second embodiment.
17 is a circuit diagram showing a configuration of a logical operation circuit in the print data correction circuit of FIG. 16. FIG.
FIG. 18 is a graph showing the relationship between gradation data and dot diameter in the second embodiment.
FIG. 19 is a diagram illustrating the effect of dot diameter correction according to the second embodiment.
FIG. 20 is a diagram showing a configuration of a third embodiment of the image recording apparatus of the present invention.
FIG. 21 is a block diagram illustrating a configuration of a print data correction circuit according to a third embodiment.
22 is a circuit diagram showing a configuration of a logical operation circuit in the print data correction circuit of FIG. 21. FIG.
FIG. 23 is a graph showing the relationship between gradation data and dot diameter in the third embodiment.
FIG. 24 is a diagram illustrating the effect of dot diameter correction according to the third embodiment.
FIG. 25 is a diagram showing a configuration of a fourth embodiment of the image recording apparatus of the present invention.
FIG. 26 is a block diagram illustrating a configuration of a print data correction circuit according to the fourth embodiment.
27 is a circuit diagram showing a configuration of a logical operation circuit in the print data correction circuit of FIG. 26. FIG.
FIG. 28 is a graph showing the relationship between gradation data and dot diameter in the fourth embodiment.
FIG. 29 is a diagram illustrating the effect of dot diameter correction according to the fourth embodiment.
FIG. 30 is a diagram illustrating a configuration of a general electrophotographic printer.
31 is a time chart at the time of printing by the electrophotographic printer of FIG. 30. FIG.
32 is a time chart at the time of printing of the electrophotographic printer of FIG. 30. FIG.
FIG. 33 is a circuit diagram of an LED head of a general electrophotographic printer.
FIG. 34 is a diagram showing a structure of an LED head and a lens array of a general electrophotographic printer.
FIG. 35 is a diagram for explaining an MTF of a lens array.
FIG. 36 is a graph showing a measurement example of MTF of a lens array.
FIG. 37 is a diagram for explaining the light intensity distribution of an LED light-emitting element.
[Explanation of symbols]
1 print control unit, 2 ROM, 3, 3A, 3B, 3C print data correction circuit, 4 gradation LED head.

Claims (9)

Image recording in which an electrostatic latent image is formed by exposing a charged photoreceptor with a plurality of driven elements , and a toner image formed by developing the electrostatic latent image is transferred to a recording medium. In the device
Storage means for storing drive data for driving the driven elements for each driven element;
Drive data of each of the driven element corresponding to the target dot and the driven element corresponding to at least one other dot in the predetermined area including the target dot is read from the storage unit, and the read drive data and the external data A calculation unit that generates corrected print data from the print data of the target dot input from the control unit;
The calculation means obtains a sum of drive data values of driven elements corresponding to dots to be printed among the dots in the predetermined area, and divides the obtained sum by the number of dots to be printed. The average value of the drive data value of the driven element corresponding to each dot in the predetermined area is obtained by subtracting the drive data value of the driven element corresponding to the target dot from the average value, and the subtraction result , The value obtained by adding the print data value of the dot of interest is the value of the corrected print data,
An image recording apparatus that performs printing by driving a driven element corresponding to the target dot using the corrected print data. The image recording apparatus according to claim 1 , wherein the print data is binary data. The image recording apparatus according to claim 1 , wherein the print data is multi-value data. The predetermined area is an area including a target dot and a dot adjacent to the target dot;
It said calculation means and generates said correction print data based on the print data of remarked dots inputted from the driving data and the control unit of the driven elements corresponding to each of the focused dot and the adjacent dot The image recording apparatus according to any one of claims 1 to 3 . The predetermined area is an area including a target dot, an adjacent dot of the target dot, and a dot adjacent to the adjacent dot;
The correction print said calculation means on the basis of the print data of the noted dot, the adjacent dots and the respective adjacent dots in adjacent dots input from the control unit and the drive data of the corresponding driven element the remarked dots 4. The image recording apparatus according to claim 1, wherein data is generated. The predetermined area is an area where dots to be printed are continuous including the target dot,
The calculation means includes driving data for the driven element corresponding to the target dot, driving data for the driven element corresponding to a dot located at an end of the predetermined area, and print data for the target dot input from the control unit. The image recording apparatus according to any one of claims 1 to 3, wherein the corrected print data is generated based on: The image recording apparatus according to any one of claims 1 to 6, wherein the driven element is a tone LED element. The driven element is a light emitting element;
A light collecting member for collecting the light emitted by the light emitting element;
The image recording apparatus according to any one of claims 1 to 6, wherein the drive data stored in the storage means is data based on light intensity obtained through the light collecting member. With a table that matches the light intensity and the dot diameter,
The drive data is image recording apparatus according to claim 8, characterized in that the dot diameter data obtained by the intensity of the light condensed on the condensing member in correspondence with the dot diameter of the table.

Images