JPH0664210A - Recording apparatus - Google Patents

Abstract

PURPOSE:To uniformize recording density by suppressing the falling of the temp. of a recording head by driving a recording head on a final line on the basis of reversal data when the recording of white data is continued. CONSTITUTION:In the recording part 102 controlled by the control part 101 of a facsimile device, a thermal head 13 being a line head is equipped with a shift resister 130 for inputting the serial recording data or shift block of one line, a latch circuit 131 and a heating element 132 consisting of heating resistors corresponding to one line. Recording is performed according to line data but, in this case, when the image data of a standard mode is decomposed into four lines of a superfine mode and all of data are white data, the signal outputted from a data forming part is set to an H-level and inversion data is transmitted to the thermal head 13 to correct the temp. of a heat generation inhibitor 132.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for recording an image on a recording medium by a recording head.

[0002]

2. Description of the Related Art Conventionally, it has been known that a facsimile machine or the like performs a smoothing process on image data received in a standard mode and records the image data based on the smoothed image data. In the recording by such smoothing, for example, the image data of one line in the standard mode is converted into the image data of four lines in the super fine mode and recorded.

[0003]

The ratio of black information and white information in the standard mode one-line image data before the smoothing process remains largely characteristic even after the smoothing process. Therefore, paying attention to the temperature of each heating resistor of the thermal head, the image data in the standard mode generates heat depending on whether electricity is applied to all the heating elements like a ruled line or when almost no black information is included. A temperature difference occurs in the resistors, and a large difference in recording density occurs between the heating resistors, which causes a deterioration in the quality of the smoothed recording image.

The present invention has been made in view of the above-mentioned conventional example, and when white information is continuously recorded, the temperature of the recording head is prevented from lowering by driving the recording head with the inverted data in the last line. It is an object of the present invention to provide a recording apparatus having a uniform recording density.

Further, according to the present invention, the number of black dots is calculated for each block of each recording element of the recording head, and recording control is performed in accordance with the number of black dots, thereby performing recording due to variations in the number of recording dots in each block. An object of the present invention is to provide a recording device that suppresses fluctuations in density.

[0006]

In order to achieve the above object, the recording apparatus of the present invention has the following constitution. That is,
A recording device for recording an image on a recording medium by a recording head, the storage device storing input image data,
Recording means for recording one line of the image data stored in the storage means over a plurality of lines; and a plurality of lines corresponding to the one line when one line of the image data does not include a recording dot. When recording the final line, the recording data is inverted to drive the recording head.

[0007]

In the above structure, when one line of the image data stored in the storage means for storing the input image data is recorded over a plurality of lines, one line of the image data contains a recording dot. If there is not, when the last line of a plurality of lines corresponding to the one line is recorded, the recording data is inverted and the recording head is driven.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing an electrical connection between a control unit 101 and a recording unit 102 of a facsimile apparatus according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing a schematic configuration of the facsimile apparatus according to the first embodiment. It is a figure.

First, the schematic construction of the facsimile apparatus of the first embodiment will be described with reference to FIG. In FIG. 2, 10
A reading unit 0 photoelectrically reads a document and outputs it as a digital image signal to the control unit 101, and includes a document feeding motor, a CCD image sensor, and the like (not shown). Next, the configuration of the control unit 101 will be described.

Reference numeral 110 denotes a line memory for storing image data of each line of the image data, which is stored as an image of one line from the reading unit 100 at the time of transmitting or copying an original, and is used for receiving the image data. At this time, 1-line data of the decoded received image data is stored. Then, the stored data is output to the recording unit 102 to form an image. An encoding / decoding unit 111 encodes image information to be transmitted by MH encoding or the like, and decodes the received encoded image data to convert it into image data. Further, reference numeral 112 is a buffer memory for storing the coded image data transmitted or received. Each unit of these control units 101 is controlled by a CPU 113 such as a microprocessor. This CPU 113 is provided in the control unit 101.
Besides, a ROM 114 for storing the control program of the CPU 113 and various data, a RAM 115 for temporarily storing various data as a work area of the CPU 113, and the like are provided.

Reference numeral 102 denotes a recording section which has a thermal line head and records an image on a recording sheet by a thermal transfer recording method. Reference numeral 103 denotes an operation unit including various function instruction keys for starting transmission, an input key for a telephone number, etc., and 103a is a switch for instructing the type of the ink sheet 14 to be used.
When 03a is on, it indicates that a multi-print ink sheet is installed, and when it is off, a normal ink sheet (one-time sheet) is installed. A display unit 104 is usually provided adjacent to the operation unit 103 and displays various functions and the state of the device. Reference numeral 105 denotes a power supply unit for supplying electric power to the entire device. Also, 1
06 is a modem (modulator / demodulator), 107 is a network controller (NC)
U) and 108 are telephones.

FIG. 1 is a diagram showing the electrical connection between the control unit 101 and the recording unit 102 in the facsimile apparatus of the first embodiment, and the portions common to the other drawings are designated by the same reference numbers. The thermal head 13 is a line head. The thermal head 13 has a shift register 130 for inputting serial recording data for one line and a shift clock, and a shift register 130 by a latch signal.
The latch circuit 131 for latching the data of 1 is provided with a heating element 132 including a heating resistor for one line. Here, the heating resistor 132 is driven by being divided into m blocks (m = 4 in this embodiment) indicated by 132-1 to 132-m. Further, 133 is a temperature sensor for detecting the temperature of the thermal head 13. The output signal 42 of the temperature sensor 133 is A / D converted in the control unit 101 and input to the CPU 113. As a result, the CPU 113 detects the temperature of the thermal head 13,
The pulse width of the strobe signal is changed according to the temperature, or the driving voltage of the thermal head 13 is changed to change the energy applied to the thermal head 13 according to the characteristics of the ink sheet 14. Reference numeral 116 is a programmable timer, which starts time counting when the time counting time is set by the CPU 113 and the start of time counting is instructed. Then, it operates so as to output an interrupt signal, a time-out signal, etc. to the CPU 113 at each designated time.

Reference numeral 117 denotes a head drive control circuit, which is a control unit 1.
The serial recording data 43a from 01, the shift clock 43b, the latch signal 44, the recording start signal 45, and the like are input, and the serial data 307 to be output to the thermal head 13, the shift clock 308, the latch signal 309, and the strobe signal 46 are input. In addition to outputting, the end signal 47 indicating the end of recording the one-line data output from the control unit 101 is output to the control unit 101. This configuration will be described later in detail with reference to FIG.

The type (characteristic) of the ink sheet 14
May be determined by detecting the switch 103a of the operation unit 103 described above, a mark printed on the ink sheet 14, or the like, and the mark, cutout or protrusion attached to the ink sheet cartridge may be detected. It may be determined and performed.

A driver circuit 36 drives the cutter 15 so as to mesh with it, and includes a motor for driving the cutter. Reference numeral 39 denotes a paper discharge motor that rotationally drives a paper discharge roller for discharging recorded recording paper. 35,4
Reference numerals 8 and 49 denote driver circuits for rotationally driving the corresponding sheet discharge motor 39, recording sheet transport motor 24, and ink sheet transport motor 25, respectively. The paper discharge motor 39, the recording paper transportation motor 24, and the ink sheet transportation motor 25 are stepping motors in this embodiment, but the invention is not limited to this and, for example, D
It may be a C motor or the like.

FIG. 3 shows the head drive control circuit 11 of this embodiment.
In the block diagram showing the configuration of No. 7, the same parts as those in the above-mentioned drawings are indicated by the same numbers.

In FIG. 3, a recording control unit 301 receives the latch signal 44 and the recording start signal 45 from the control unit 101, and outputs various signals such as a strobe signal 46, a selection signal, and a line end signal 46. ing. A data generation unit 302 receives the serial recording data 43a and the shift clock 43b from the control unit 101 and divides the image data according to the signals LS0 and LS1 from the recording control unit 301. That is, the data generator 302
If you input the data for one line, it will be stored and
Selection signals LS0, LS input from the recording control unit 301
According to 1, the output of serial line data is started by the transfer start signal XSST. An inverted data generation unit 303 inverts the image data of the previous line by the signal XSST and outputs it when the selection signals LS0 and LS1 from the recording control unit 301 are both at the high level. Both 310 and 311 are AND circuits, and select data from either the data generation unit 302 or the inverted data generation unit 303 by a signal 306 described later and output it to the OR circuit 312.

The serial recording data 43a is the clock 43.
When the black data is input to the high level and the white data is input to the low level in synchronization with b, the data is transferred to the data generation unit 302 and the inverted data generation unit 303. Here, the number of bits of the data of one line is “2048” bits, and the frequency of the data transfer clock 43b is 3.3 MHz.
As a result, the time required to transfer one line of data is about 0.
It becomes 62 ms. The data generation unit 302 performs data conversion from the standard mode (standard mode) to the super fine mode or data conversion from the fine mode to the super fine mode according to the transferred image data. In this embodiment, the data conversion from the standard mode to the super fine mode will be described as an example, but it goes without saying that the present invention is not limited to this.

In the data generation unit 302 of this embodiment, 1
When the data for the standard mode for the line is input, the recording data for four lines in the super fine mode is generated.
The signals LS0 and LS1 output from the recording control unit 301
Is a selection signal for instructing a line of print data output from the data generation unit 302. Also, the signal XS
ST is a signal for instructing the data generation unit 302 to start data transfer to the thermal head 13. Thirty
Reference numeral 4 is a signal for instructing the data generation unit 302 from the recording control unit 301 to output the latch signal 309.

Reference numeral 305 denotes data obtained by inverting the data of the previous line output from the inverted data generation unit 303. 306 (ALW) is a signal that becomes high level when the image data is decomposed into four lines in the data generation unit 302 and all of the four lines are all white lines. 307 is serial recording data output to the thermal head 13, 308 is its synchronization clock, and 309 is
The latch signal output from the data generator 302 to the thermal head 13 is indicated by the latch signal 304 from the recording controller 301. The selection signal LS
0 and LS1 will be described as follows: (LS0, LS1) =
When (0,0), 1 of data divided into 4 lines
The second line is selected and (LS0, LS1) = (1,
0), the second line data is (LS0, LS
When 1) = (0,1), the third line data is
When (LS0, LS1) = (1, 1), the fourth line data is selected. Here, 0 represents a low level and 1 represents a high level.

FIG. 4 is a flow chart showing the control by the control unit 101 of the facsimile apparatus of this embodiment. The control program for executing this processing is stored in the ROM 114. This process is started when the facsimile signal is received and the recording process for one line becomes possible.

First, in step S1, the print data for one line in the standard mode is output to the head drive control circuit 117. Next, in step S2, the latch signal 44 is output. As a result, the operation of the recording control unit 301 shown in the flowchart of FIG. 5 described later is started. Next, the process proceeds to step S3, the rotation of the recording paper transportation motor 24 is started to start the transportation of the recording paper, and the rotation of the ink sheet transportation motor 25 is started to start the transportation of the ink sheet in step S4. Next, in step S5, the start signal 45
Is output. As a result, the actual recording operation is started.

Next, in step S6, the recording controller 30
It is determined whether or not the end of the recording process for one line from 1 is notified by the signal 47, and if not, step S
Proceed to 7 to see if the next line data has been prepared. When the next line data is prepared, the process proceeds to step S8 and the line data is output to the data generation unit 302. Here, it is assumed that the data generation unit 302 has a memory capacity capable of storing at least two lines of recording data.

When the recording control unit 301 notifies the end of recording of one line in this way, the process proceeds to step S9, and it is determined whether or not the recording of one page is completed, and if not, step S1.
In step 0, it is determined whether the next line data has already been transferred to the data generation unit 302 of the head drive control circuit 117. If it has been transferred, proceed to step S2,
If not, the process proceeds to step S1 to transfer data.

When the recording of one page is completed in step S9, the process proceeds to step S11, the recorded recording paper is conveyed by a predetermined amount, the cutter 15 is driven to cut the recording paper, and step S11 is performed.
At 12, the recorded recording paper is ejected and the unrecorded portion of the recording paper is returned by a predetermined amount to prepare for the next recording.

Next, referring to the flowchart of FIG.
The operation of the recording control unit 301 of the head drive control circuit 117 will be described.

FIG. 5 is a flowchart showing the operation of the recording control unit 301. First, in step S21, the input of the latch signal 44 from the control unit 101 is waited for. When this latch signal 44 is input, it means that the recording data for one line has been transferred to the data generating unit 302, so that the process proceeds to step S22, the selection signals LS0 and LS1 are both set to 0, and the transfer start signal XSST is set. Output. As a result, one line of data is transferred from the data generator 302 to the thermal head 13. Next, in step S23, the data generator 3
The number of clocks of the clock signal 308 output from 02 is counted to determine whether the transfer of one line is completed. When the data transfer of one line is completed, step S24
To output the latch signal 304 to the data generator 30.
2 is instructed to output the latch signal 309, and then in step S26, the strobe signals STB0 to STB3 are sequentially output to record one line.

Simultaneously with the output of this strobe signal, in step S26, the selection signal is switched and the transfer start signal XSST is output to the data generator 302. As a result, the next line data is transferred from the data generator 302 to the thermal head 13. Next, in step S27, 1
It is checked whether or not the line recording process is completed, and if completed, the process proceeds to step S28, and it is checked whether or not both the selection signals LS0 and LS1 are 1, that is, whether or not the line is the fourth line in the super fine mode. If not, the process proceeds to step S23, but if both are 1, the process proceeds to step S29 to output the latch signal 304 to the data generation unit 302. As a result, the data generator 302 causes the latch signal 30
9 is output to the thermal head 13, and the data on the fourth line is latched by the latch circuit 131.

Next, in step S30, it is checked whether or not the signal 306 is at the high level, and if it is at the high level, the process proceeds to step S31 in which only the strobe signals STB0 and STB1 are supplied to the thermal head 13 so that actual recording is not performed.
Output to. This process will be described later in detail with reference to the timing chart of FIG. On the other hand, when the signal 306 is not at the high level, the process proceeds to step S32, the strobe signals STB0 to STB3 are output as in the normal recording, and the step S3 is performed.
In step 3, the control unit 101 is notified of the end of recording of one line in the standard mode (four lines in super fine) by the signal 47.

FIG. 5 is a timing chart showing the timings of various signals in the data generator 302, in which 1-line data in the standard mode is input and converted into 4-line data (1-1 to 1-4) in the super fine mode. It shows the case of recording. Note that, in FIG. 5, the data (1-1) that is the first one-line data is shown from the time when it has already been transferred to the thermal head 13 and latched by the latch circuit 131.

First, in order to instruct the transfer of the data of the second line, the recording control section 301 sets (LS0, LS1) =
As (1, 0), a pulse signal is output as the signal XSST (step S22). As a result, the data (1-
The transfer of 2) is started. After that, the recording control unit 301 outputs the strobe signals STB0 to STB3 (step S25) and performs recording with the line data (1-1).

In this embodiment, one line of super fine is recorded by scanning one line of recording data in the standard mode four times. The pulse width of this one-time strobe signal is about 0.15 ms, and one line data in the standard mode is recorded in about 10 ms. The pulse widths of the strobe signals STB0 to STB3 are variable depending on the temperature value of the thermistor 133 of the thermal head 13 and the recording cycle determined by the time from the end of recording of the previous line to the start of recording of the current line.

As is apparent from the timing chart of FIG. 5, it is understood that the next line data transfer process is completed with a margin during the recording time for one line in the super fine mode. After the recording of the first line data (1-1) in the super fine mode is completed, the latch signal 304 is sent from the recording control unit 301 at timing T1.
Is sent, and at the same time, the data generation unit 302 sends a latch signal 309 to the thermal head 13. As a result, the line data (1-2) transferred and stored in the shift register 130 of the thermal head 13 is latched by the latch circuit 131.

After sending the latch signal 309, the recording control unit 301 performs the next data transfer (LS0, LS1).
The signal XSST is transmitted as = (0,1) (step S26). Accordingly, the data generation unit 302 starts the transfer of the next line data (1-3). The recording control unit 301 outputs the strobe signals STB0 to STB3 to the thermal head 13 while sending the line data (1-3). As a result, recording with the line data (1-2) is performed.

When the recording of the line data (1-2) is finished in this way, the next line data (10
3) is latched in the latch circuit 131. After that, the recording control unit 301 sets (LS0, LS1) = (1, 1), and instructs the data generation unit 302 to transfer the next line data (1-4) by the signal XSST. Where (LS0, LS
When 1) = (1,1), the inverted data generation unit 303
From the inversion data generation unit 303 is also started by the signal XSST. Here, the line data sent from the inversion data generation unit 303 is data obtained by logically inverting the image data of the previous line as described above.

Thus, in this case, data is transmitted from both the data generation section 302 and the inverted data generation section 303 by the signal XSST, but as described above, the signal 306 output from the data generation section 302 is a standard signal. This is a signal that becomes a high level when the image data of the mode is decomposed into four lines of the super fine mode and the recording data for the four lines are all white data. Therefore, when the signal 306 is at high level, the AND circuit 31
0 is opened and the print data output from the reverse data generation unit 303 is transferred to the thermal head 13. Further, when the signal 306 is at the low level, only the AND circuit 311 is opened, the data transfer from the inverted data generation unit 303 is not performed, and the line data from the data generation unit 302 is transferred.

Thus, when the signal 306 is at the high level, the inverted data of the previous line is transferred to the thermal head 13. The energization at the time of transferring the inversion data is for the purpose of temperature correction of the heating resistor 132 of the thermal head 13, so energization of the portion indicated by 401 in FIG. 5 is omitted so that recording is not performed. Thus, the energization process for only two scans is performed (step S31).

An example of so-called smoothing processing for converting such a standard mode facsimile image into a super fine mode received image will be described with reference to FIGS.

In these figures, the pixel at the coordinate E4 is the pixel of interest, and E4 is on the upper side (E4U: upper part of the standard, equivalent to the first fine line) and on the lower side (E4D: lower part of the standard, four fine lines). (Equivalent to eyes). FIG. 7 shows a condition in which the pixel of interest (E4) is white and E4D is black. Further, FIG. 8 shows the target pixel (E4).
Indicates that white is white and E4U is black. Further, FIG. 9 shows the condition that the target pixel (E4) is black and E4D is white, and FIG. 10 is the target pixel (E4) is black and E4U.
Indicates the condition that turns white.

Although these figures show an example of converting the standard mode facsimile image into the fine mode cotton density, in order to convert the standard mode received image information into the super fine mode cotton density, It is easily conceivable that the same processing is performed again on the image information converted from the standard mode to the fine mode to convert it into the super fine cotton density. Various smoothing methods have been considered, and the example shown here is already known.

An example of recording an image by such smoothing processing is shown in FIG. FIG. 11A shows image data in the standard mode. Then, FIG. 11B
Shows an example of image data in the super fine mode converted based on the image data.

As described above, according to the first embodiment,
When the heating resistor of the thermal head is not continuously energized during smoothing recording, by energizing and heating the thermal head, it is possible to prevent uneven density due to temperature variation of the heating resistor.

Next, a method of driving the thermal head 13 according to the second embodiment of the present invention will be described with reference to FIGS.

FIG. 12 shows the thermal head 13 of the second embodiment.
In the figure showing the configuration of the above, the same parts as those in the above-mentioned drawings are indicated by the same numbers. Here, it is assumed that the heat generating resistors 132 of the thermal head 13 are composed of a total of 1728 elements, and these heat generating resistors 132 are divided into five blocks and driven to generate heat. Reference numeral 134 denotes a gate circuit for driving the heating resistor 132, which selects the heating resistor to be energized according to the recording data output from the latch circuit 131. Each of XSTB1 to XSTB5 is a strobe signal corresponding to each block of the heating resistor 132.

FIG. 13 is a diagram showing the arrangement of heating resistors in the thermal head 13. Here, as is apparent from comparison with FIG. 12, since the adjacent heating resistors are arranged in different blocks, there is no possibility that the adjacent heating resistors are simultaneously energized to generate heat.

FIG. 14 is a timing chart showing an example of the output timing of these strobe signals. As is clear from this timing chart, further adjacent blocks are arranged to be energized with a certain time interval. In this way, the influence of the heat generation temperature between the adjacent heat generating resistors can be eliminated, and the recording quality can be kept high.

FIG. 15 is a diagram showing the structure of the main part of the facsimile apparatus according to the third embodiment of the present invention, particularly the connection part between the control part 101a and the thermal head 13. The same parts as those in the above-mentioned drawings are indicated by the same reference numerals, and the description thereof will be omitted. Further, in FIG. 15, the configuration and connection of the recording unit 102 are the same as those in FIG. 1 described above, and therefore they are also omitted.

FIG. 16 is a block diagram showing the structure of the thermal head 13. The thermal head 13 has a structure of 204
It has eight heat generating resistors, and one block is divided into four blocks of 512 heat generating resistors and driven for heat generation. The black ratio determination circuit 118 of FIG. 15 calculates the ratio of black data included in the data of each block of the thermal head 13. The black ratio of each block thus obtained is read by the control unit 101a as data 51 from the block designated by the address data 50.

FIG. 17 is a block diagram showing the circuit configuration of the black ratio determination circuit 118 of this embodiment. In FIG. 17, 8
A black data detection circuit 01 detects black dots contained in one line of data. A counter 802 inputs a signal from the black data detection circuit 801 and counts the number thereof. Data holding circuits 803 to 805 hold input data in synchronization with the rising edge of the clock signal 809. A multiplexer 806 receives the address data 50 from the control unit 101a and outputs the output value of the holding circuit corresponding to the address to the data bus 51. A latch clock generation circuit 807 inputs the shift clock 43b from the control unit 101a, and outputs the latch clocks of the holding circuits 803 to 805 and the clear signal of the counter 802.

With the above configuration, when the serial recording data 43a and the shift clock 43b are input from the control unit 101a, the output Q / (/ indicates negative) of the flip-flop 810 becomes low level at the rising edge of the clock 43b. . Then, when the shift clock 43b next becomes low level, the output of the NOR gate 811 becomes high level and the counter 802 is incremented by one. In this way, the number of black dots is sequentially counted by the counter 802, and when the count value of the counter 808 reaches a predetermined value (here, for example, 512 corresponding to one block), its output OUT
1 goes high. This makes the counter 809 +
When it is set to 1, its output (OUT) becomes high level, and the content of the counter 802 is latched in the holding circuit 803. After that, the counter 802 is reset by the output (OUT2) of the counter 808 to prepare for counting the black data of the next block.

FIG. 18 is a block diagram showing the structure of the counter 808.

In FIG. 18, 820 is a counter for inputting and counting a clock signal (CK), and 822 is a data setting circuit (register) in which a predetermined numerical value ("512" in this embodiment) is set. The output values of the counter 820 and the data setting circuit 822 are compared by the comparison circuit 821, and if they match, a high level signal is output. 8
A flip-flop 23 latches the signal from the comparison circuit 821 in synchronization with the clock signal (CK). Therefore, in this embodiment, 512 shift clocks 43
When b is counted, OUT1 is output at a high level for one cycle of the shift clock 43b, and then the shift clock 43b is output.
When b becomes low level, the output OUT2 is output at low level.

FIG. 19 is a block diagram showing the structure of the counter 809.

Reference numeral 831 is a 2-bit counter, which increments the content by 1 at the rising edge of the clock (CK). Then, the NAND circuit 832 and the AND circuit 833 prohibit the subsequent counting when the count value becomes “3”.

The operation of the circuit of FIG. 17 configured as above will be described with reference to the timing chart of FIG.

After the flip-flops and counters are reset by the latch signal 44, the serial data 4
3a and the shift clock 43b are input, the counter 808 starts counting the shift clock, and the flip-flop 810 outputs the Q value each time black data is input.
/ Set output to low level. Thus, the NOR circuit 811
Thus, the clock of the counter 802 is created, and the counter 802 counts the number of black data. When the counter 808 counts 512 shift clocks 43b, OUT1 is output at timing T1. As a result, the content (4) of the counter 802 is latched in the holding circuit 803.

Next, when 512 pieces of all black data are continuously input, the content (512) of the counter 802 is set in the holding circuit 803 at the timing T2, and the holding circuit 8 is held.
The content (4) stored in 03 is held in the holding circuit 804. Similarly, the next shift clock 43b is 512
When input once (timing T3), the content (4) of the holding circuit 804 is stored in the holding circuit 805 and the holding circuit 803 (51).
The contents of 2) are shifted and held in the holding circuit 804 and the contents of the counter 802 in the holding circuit 803, respectively.
At this time, the output of the counter 831 of FIG. 19 becomes "11" and the output of the AND circuit 832 becomes low level. Accordingly, when 512 shift clocks 43b are counted next time, the clocks of the holding circuits 803 to 805 are not output, and the counter 802 keeps the number of black dots of the fourth block stored.

Therefore, the control unit 101a outputs the address data 50 and reads the data 51 after transferring the recording data of one line to the thermal head 13 and before outputting the latch signal 44, whereby the thermal head 13 is read.
The number of black dots corresponding to each block of the heating resistor 132 can be read and detected.

FIG. 21 is a flow chart showing the recording operation in the facsimile apparatus of the third embodiment of the present invention, and the control program for executing this processing is stored in the ROM 122. This process is started by creating image data for recording on one line, and first, in step S41, the latch signal 44 is output to determine the black ratio determination circuit 11
Reset each part of 8. Next, in step S42,
The recording data for one line is output to the thermal head 13. Next, in step S43, the address signal 50 is
(0,0) to (1,1) are sequentially output, and the number of black dots corresponding to each heating resistor block of the thermal head 13 is obtained. Next, in step S44, the temperature of the thermal head 13 is detected by the temperature sensor 133, and the strobe signals STB1 to STB for energizing each block are detected based on the temperature and the number of black dots corresponding to each block.
Each energization pulse width of B4 is calculated (step S4
5). This can be determined, for example, by storing a look-up table or the like in which the pulse width of the strobe signal is stored corresponding to the temperature of the thermal head 13 and the number of black dots in the ROM 122 and referring to this table.

When the width of the strobe pulse is thus determined, the process proceeds to step S46, the latch signal 44 is output,
The conveyance of the recording paper is started in step S47, and the conveyance of the ink sheet is started in step S48. Next, proceeding to step S49, energization of each block of the thermal head 13 is started. After the energization of one block is started in step S49, the process proceeds to step S50 and step S45.
It is checked whether or not the energization time of the block, which has been determined in step S4, has elapsed. If the energization time has not elapsed, the process proceeds to step S51 to check whether the next line data is ready. When the next line data is ready, step S52
Then, in step S42, the next line data is transferred to the thermal head 13.

When the energization time has elapsed in step S50, the process proceeds to step S53 to check whether the energization of all blocks (here, 4 blocks) of the thermal head 13 has been completed. In step S54, it is determined whether or not one page has been recorded. If the recording of one page is not completed, step S5
Go to step 5 to see if the next line data has been transferred to the thermal head 13. If the transfer of the next line data has been completed, the process returns to step S43, and if not, the process returns to step S42 to execute the above-described processing.
When one page is finally recorded in this way, step S5
In step 6, the recorded recording paper is cut into a predetermined length, and the cut recording paper is discharged to the outside of the apparatus.

FIG. 23 is a block diagram showing a schematic structure of a thermal head which is a modification of the third embodiment. Here, by providing the temperature sensors 231, 232, 233, 234 for each block of the heating resistor 132 of the thermal head 13, and detecting the temperature of each block together with the number of black dots in each block as described above, The energizing pulse width of each block is determined accordingly. In this process, the temperature of each block of the thermal head 13 is detected by the sensors 231 to 23 in step S44 of FIG.
4 and the pulse width of the strobe signal of each block is determined based on the temperature value of each block and the number of black dots in each block in step S45. As a result, it is possible to perform the energization control according to the temperature of the thermal head 13 with higher accuracy.

FIG. 24 is a diagram for explaining still another embodiment. In the above-described embodiment, since the clock signal of the black ratio determination circuit 118 is the shift clock 43b in order to simplify the circuit, the number of dots to be counted is 2
There was a bit error. Therefore, in this embodiment, in order to eliminate such an error, a clock signal BCK having a higher frequency is input, and the number of shift clocks is counted by synchronizing the signal BCK and the shift clock 43b to increase the number of shift clocks. The number of black dots can be accurately counted.

The present invention may be applied to either a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program for implementing the present invention to a system or an apparatus.

[0066]

As described above, according to the present invention, when white information is continuously recorded, the temperature of the recording head can be prevented from lowering by driving the recording head with the reverse data in the last line. There is an effect that the recording density can be made uniform.

[Brief description of drawings]

FIG. 1 is a diagram showing an electrical connection between a control unit and a recording unit in a facsimile apparatus of this embodiment.

FIG. 2 is a block diagram showing a schematic configuration of a facsimile apparatus of this embodiment.

FIG. 3 is a block diagram showing a configuration of a head drive control circuit of this embodiment.

FIG. 4 is a flowchart showing a recording process in the facsimile apparatus according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing a process of a recording controller of the head drive circuit according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a recording timing in which the thermal head in the facsimile apparatus according to the present embodiment is divided into four and writing is performed four times.

FIG. 7 is a diagram showing an example of a smoothing process for creating fine mode image data from standard mode image data.

FIG. 8 is a diagram illustrating an example of smoothing processing for creating fine mode image data from standard mode image data.

FIG. 9 is a diagram illustrating an example of smoothing processing for creating fine mode image data from standard mode image data.

FIG. 10 is a diagram showing an example of a smoothing process for creating fine mode image data from standard mode image data.

FIG. 11 is a diagram showing a specific recording example in the facsimile apparatus of the picture of this embodiment.

FIG. 12 is a block diagram showing a configuration of a thermal head according to a second embodiment of the present invention.

FIG. 13 is a diagram showing an arrangement of heating resistors of a thermal head according to a second embodiment of the present invention.

FIG. 14 is a diagram showing a timing of energizing the thermal head according to the second embodiment of the present invention.

FIG. 15 is a diagram showing an electrical connection between a control unit and a recording unit in the facsimile apparatus of the third embodiment of the present invention.

FIG. 16 is a diagram showing a configuration of a thermal head in a facsimile apparatus according to a third embodiment of the present invention.

FIG. 17 is a block diagram showing a configuration of a black ratio determination circuit in a facsimile apparatus according to a third embodiment of the present invention.

FIG. 18 is a block diagram showing a configuration of a counter 808 of the black ratio determination circuit according to the third embodiment of the present invention.

FIG. 19 is a block diagram showing a configuration of a counter 809 of the black ratio determination circuit according to the third embodiment of the present invention.

FIG. 20 is a timing chart showing the operation of the black ratio determination circuit of the third embodiment.

FIG. 21 is a flowchart showing a recording process in the facsimile apparatus of the third embodiment of the present invention.

FIG. 22 is a flow chart showing a recording process in the facsimile apparatus of the third embodiment of the present invention.

FIG. 23 is a block diagram of a thermal head showing a modification of the third embodiment of the present invention.

FIG. 24 is a diagram showing inputs and outputs of a black ratio determination circuit of another embodiment.

[Explanation of symbols]

 13 thermal head 43a serial data 43b shift clock 101 control unit 102 recording unit 117 head drive control circuit 118 black ratio determination circuit 130 shift register 131 latch circuit 132 heating resistor 301 recording control unit 302 data generation unit 303 inversion data generation unit 802 808, 809, 820, 832 Counter 803, 804, 805 Holding circuit 821 Comparison circuit 822 Data setting circuit

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display location B41J 29/00 H04N 1/23 102 A 9186-5C B41J 3/20 115 E 8804-2C 29/00 U

Claims (3)

[Claims] 1. A recording apparatus for recording an image on a recording medium by a recording head, comprising a storage unit for storing input image data, and one line of the image data stored in the storage unit over a plurality of lines. Recording means for recording, and when recording dots are not included in one line of the image data, when recording the last line of a plurality of lines corresponding to the one line, the recording data is inverted to cause the recording head to move. A recording device comprising: a drive unit that drives the recording medium. 2. A recording apparatus for recording an image on a recording medium by a recording head, the recording unit performing recording by dividing a recording element of the recording head into a plurality of blocks and driving the block, and the recording head. Temperature detecting means for detecting the temperature of the block, counting means for counting the number of recording dots corresponding to each of the blocks, based on the number of recording dots and the temperature of the recording head, the drive energy of each of the blocks A recording device comprising: a means for determining. 3. The recording apparatus according to claim 2, wherein the temperature detecting unit is configured to detect the temperature of each of the blocks.