JPS61150571A - Picture forming device - Google Patents

Abstract

PURPOSE:To reduce a memory and to simplify a circuit configuration by storing the data of a scanning line at every horizontal synchronizing signal and performing the transfer of the content of the memory on a transferred material by one scanning line with a transferring material before next vertical synchronizing signal is supplied. CONSTITUTION:Picture information corresponding to one picture is supplied from a controlling section to a buffer 81 in the color converting section. The signals supplied include chrominance components of R, G, B, vertical synchronizing signals that indicate the switching of one picture, horizontal synchronizing signals that indicate the discrimination at every line, clock signals etc. Then, the transfer data (picture signals of R, G, B) of the first line are stored in a RAM82 through the buffer 81. The picture signals of the first line stored in the RAM82 are converted to chrominance components by a ROM83 for color conversion and outputted to a head driving circuit 62. Thus, the head driving circuit 62 makes the printing corresponding to one scanning line by driving a thermal head 8 according to the printing data supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thermal transfer type image forming apparatus that is applied to, for example, output recording of a meter or a word processor.

[Technical backstory of the invention]

2. Description of the Related Art In recent years, as one of the non-impact printing techniques, a thermal transfer type color (multicolor) image forming apparatus that is small, inexpensive, noiseless, and capable of recording on plain paper has been developed and put into practical use.

Normally, this type of image forming apparatus operates the thermal head with paper and a thermal transfer ribbon interposed between a platen and a thermal head (thermal head) to apply ink on the thermal transfer ribbon to each dot row. An image is formed by transferring print data line by line onto paper.

However, in the conventional apparatus as described above, when transferring one page of image information, one page of image information is stored in the -H memory, and this stored data is transferred to one page. Each line was taken out and transferred. Therefore, there was a problem that a large memory capacity was required and the circuit became complex.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and its object is to provide an image forming apparatus that requires less memory capacity and can be simplified in circuitry.

[Summary of the Invention] In order to achieve the above object, the present invention provides an image forming apparatus that transfers color material of a transfer material to a transfer material to form an image, in which one screen worth of image information is transferred one scanning line at a time. outputting a horizontal synchronizing signal at each break in each scanning line, and outputting a vertical synchronizing signal at each break in the image information;
Data for at least one scanning line is stored for each horizontal synchronization signal, and the stored contents are transferred for one scanning line to the transfer material by the transfer material before the next vertical synchronization signal is supplied. It was designed to do this.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 8 and 9 show a thermal transfer type image forming apparatus according to the present invention, and numeral 1 in the figures indicates a main body.

The main body 1 has a power supply section 2 at the rear and an image forming section 3 at the front, that is, the operation surface side.

The power source section 2 and the pulse motor 4 provided on the front side thereof are assembled on a main body base 6 to which support legs 5... are attached.

The image forming section 3 is provided with a conductive platen roller 7 approximately in the center of the front part of the main body 1, and a heat generating section (not shown) is generated along the axial direction of the platen roller 7 on the lower side of the platen 0-rough. A thermal head 8 is provided as a heat-sensitive head whose portion is formed into a line tod shape. This thermal head 8 is mounted on a head mounting base 9, which is mounted on a leaf spring 11 whose one end is held by a holder 10, and whose lower surface on the free end side is a plunger of a solenoid 12. It is elastically supported by a coil spring 14 attached to 13. The excitation/demagnetization operation of the solenoid 12 causes the thermal head 8 to be pressed against the platen roller 7 with a pressure suitable for thermal transfer or to be separated from the platen roller 7 by a predetermined distance. A temperature detector 68 is provided near the thermal head 8 to detect the temperature around the thermal head 8, that is, the temperature of the outside air, and the temperature generated by the heat generated by the thermal head 8. The temperature detector 68 is formed of, for example, a thermistor.

Further, a cassette holder 15 is provided inside the main body 1, and this cassette holder 15 has a thermal transfer ribbon (transfer material) 1
6 and the winding core 17 on the feeding side and winding side around which both ends are wound.
．． A ribbon cassette 19 containing 18 is attached. The thermal transfer ribbon 16 is unwound from the unwinding core 17, wound around the first and second ribbon guides 20, 21 in sequence, guided between the platen roller 7 and the thermal head 8, and guided to the first The ribbon is wound around the platen roller 7 by the second ribbon guide 20° 21 and the third ribbon guide 22. Then, after being folded back so as to be rapidly separated from the platen roller 7 via the third ribbon guide 22 (that is, peeled off from the platen opening C-roller 7), the ribbon is wound onto the winding-side winding core 18. ing.

Further, a paper mounting section 23 is provided above the power supply section 4, and a roll-shaped paper p wound around a winding core 24 is mounted thereon. Then, the paper p fed out from this mounting section 23
is wound around the paper guide 25 and guided between the platen roller 7 and the thermal transfer ribbon 16, and is also wound tightly around the platen roller 7 via a pair of presser rollers 26 and 26. It has become.

Furthermore, between the first and second ribbon guides 20.21,
A ribbon detector 27 consisting of a light emitting element 27a and a light receiving element 27b for detecting the ink correspondence state of the thermal transfer ribbon 16 is provided, and a paper guide 25 is provided.
A discharge brush (not shown) and a paper detector 28 consisting of a light emitting element and a light receiving element are provided between the presser roller 26 on the upstream side and the paper detector 28 . The ribbon detector 27 can detect the initial position (home position) of the thermal transfer ribbon 16 when the thermal head 12 is lowered and is stationary or moving.
2 is raised and the thermal transfer ribbon 16 and paper P are moving together, the position (angle) is such that the initial position of the thermal transfer ribbon 16 can be detected.

Further, a display/operation section 29 is provided at the front of the top surface of the main body 1, and this display/operation section 29 includes a power display section 30, a paper supply display section 31, a ribbon replacement display section 32, and other display sections 33. and an N source switch.

In addition, 34 is a connector, 35 is a flexible cable, and
As shown in FIG. 10, the main body 1 includes a lower cover 37
The image forming section 3, which is divided into three parts, an upper rear cover 38 and an upper front cover 39, and which is provided on the operation surface side inside the main body 1, is divided into two parts and supported by a lower frame 40 and an upper frame 41. has been done. Thereby, a lower unit 42 and an upper unit 44 which can be freely opened and closed relative to the lower unit 42 using the pivot shaft 43 of the main body 1 as a rotational fulcrum are constructed. In addition, the upper unit 4
4 includes a platen roller 7, a paper guide 25, a presser roller 26, 26, a paper detector 28, and an operation/operation unit 2.
9th grade is incorporated.

The lower unit 43 also incorporates a thermal head 8, a solenoid 12, ribbon guides 20, 21, 22, and the like.

Further, the upper unit 44 is always rotated upwardly by a push-up support mechanism 45 made of a torsion spring, and when the upper unit 44 is in the open state, the cassette holder 15
is positioned and exposed in the space between the upper unit 44 and the lower unit 42. That is, the cassette holder 15 is rotatably supported by a pivot shaft 46 on the rotation fulcrum side of the upper frame 41 provided in the upper unit 44, and the range of downward rotation is regulated by a stopper (not shown). The upper unit 44 is configured to rotate only approximately 1/2 of the full opening angle.

Therefore, by opening the upper unit 44, the ribbon cassette 19 can be attached to and removed from the cassette holder 15.

Further, the free end side of the upper unit 44 is usually fixed to the lower unit 42 by a locking mechanism 47, so that the upper unit 44 will not be opened inadvertently due to some external force. That is, a hook 48 is rotatably attached to the frontmost portion of the lower frame 40 via a pivot shaft 49, and is rotatably biased by a spring (not shown). Further, a hook hanging bar 50 is provided on the free end side of the upper frame 41. Then, when the upper unit 44 is pushed down against the push-up blade of the push-up support mechanism 45, the hook 4
8 is hooked to a hook hanging bar 50 to hold the upper unit 44 in a closed state. Also, by rotating the hook 48 in the opposite direction, the hook 48 can be rotated in the opposite direction.
8 is removed from the hook retaining bar 50, and the upper unit 44 is automatically opened by the push-up blade of the push-up support mechanism 45.

Further, as shown in FIG. 11, the control section 60 includes a color conversion section 6
1 and a head drive circuit 62, and a pulse motor 4 as a common drive source for feeding the paper P and the thermal transfer ribbon 16 via a motor drive circuit 63. , the paper detector 28, the ribbon detector 27, the display/operation section 29,
An upper unit opening/closing detector 65 is connected which turns on and off in accordance with the on and off operations of a power switch (not shown). Further, the solenoid 12 is connected via a ribbon changeover switch 67, the temperature sensor 68, and a solenoid drive circuit 69, and is also connected to an external device 70 such as a computer or word processor via an interface section 71. ing.

However, an external plan! Alternatively, when a print command (transfer command) is issued from a word processor or the like, this device operates and prints on the paper P. That is, in response to a print command, the pulse motor 4 is driven to feed the paper P and the thermal transfer ribbon 16, which are in close contact with each other, at the same speed and in the same direction, and the thermal head 8 starts heating printing (recording) to print one dot. One line of transfer data for each column is transferred. That is, in this portion, the ink on the thermal transfer ribbon 16 is heated and melted by the thermal head 8 and transferred to the paper P. In this way, by transporting the thermal transfer ribbon 16 and the paper P and performing the printing operation by the thermal head 8, the necessary information is printed on the paper 11tP.

The color conversion section 61 is configured as shown in FIG. That is, 81 is a buffer, which temporarily stores print data from the control section 60. This buffer 81 contains R as the print data.
, G, and B data signals, that is, data for determining which colors are to be printed in full degree, half degree, or not printed, clock pulse Ck, vertical synchronization signal indicating switching of one screen (■ signal ), horizontal synchronization signal (H signal) indicating line separation, Dl, mode designation signal specifying /D2 mode (for color printing) or D2s mode (for monochrome printing), odd number (ODD) field, even number ( EVE
N) An O/E signal specifying a field is supplied. The data RA N1182 contains RlGJB data signals of the print data supplied from the buffer 81, that is, data for determining which colors are to be printed in full brightness, half brightness, and no printing, in three lines for each color. It is something that remembers minutes. The color conversion ROM 83 outputs a print signal according to the signal from the data RAM 82. The selector 84 outputs a signal instructing the read address or write address of the RAM 82. When the O/E signal is not supplied from the synchronization circuit 86, the acquisition instruction circuit 85 controls the buffer 81.
The number of lines is counted by counting the number of horizontal synchronization signals @ (H signals) for each vertical synchronization signal (V signal) supplied from This is what is output.

Further, the above-mentioned import instruction circuit 85 receives 0 from the synchronization circuit 86.
When the /E signal is supplied, a capture instruction signal for instructing data capture is output in accordance with the count value of the number of lines and the 0/'E signal from the synchronization circuit 86. When the D2s mode signal is supplied from the buffer 81 as a mode designation signal, the synchronization circuit 86 controls the buffer 81.
The O/E signals supplied from the controller are alternately outputted to the capture instruction circuit 85. The write dot counter 87 starts operating in response to a capture instruction signal from the capture instruction circuit 85, and sequentially indicates write addresses in response to a clock from the buffer 181. The read dot counter 88 sequentially instructs read addresses in response to a clock signal from a control circuit (not shown). Completion of writing for each line is determined based on the count value of the write dot counter 87.

In addition, as shown in Figure 2, the above-mentioned one screen has a width of 248×
It is composed of 204 vertical pixels, and in the Dl/D2 mode, the thermal head 8 has a dot configuration of 2 horizontal x 2 vertical dots for each pixel, allowing full brightness printing, half brightness printing, or no printing. In the D2S mode, one pixel is configured as one dot.

Next, the transfer operation in the above configuration will be explained.

First, the case of DI/D2 mode (color printing) will be explained with reference to timing charts shown in FIGS. 3 and 4. For example, one screen worth of image information is now supplied from the control section 60 to the buffer 181 in the color conversion section 61. These signals include R, G, and B color signals, a vertical synchronization signal (1V signal) that indicates switching of one screen, a horizontal synchronization signal (11-1 signal) that indicates the separation of each line, and a clock signal. be done. Then, the first line transfer data (R, G, B image signals) is stored in the RAM 82 via the buffer 81. The first line image signal stored in the RAM 82 is converted into a color signal by a color conversion ROM 83 and output to the head drive circuit 62. As a result, the head drive circuit 62 drives the thermal head 8 according to the supplied print data, thereby making it possible to
Prints the number of scan lines. Next, the image signal of the first line stored in the RAM 82 is sent to the color conversion RO again.
The signal is converted into a color signal by M83 and output to the head drive circuit 62. As a result, the head drive circuit 62 prints the second line with the same content as the first line by driving the thermal head 8 according to the supplied print data. From then on.

Each time every other line of transfer data (R, G, B image signals) is stored in the RAM 82, two lines are printed. In this case, the R, G, and B signals are R
Each data is stored in the AM82 and has a 4-bit configuration, of which only the MSB and MSB-1 bits are used to perform printing after color conversion. During one frame (approximately 16.7 m5) in which data for one screen is supplied, the thermal head prints two lines and takes in data for the next line. When all the lines have been printed, the paper P is moved back and the same operation is repeated with other ink portions of the next thermal transfer ribbon 16.

Next, the case of the D2S mode (monochrome printing) will be described with reference to timing charts shown in FIGS. 6 and 7. For example, right now, one screen worth of image information is being sent from the control unit 60 in interlace mode (initially 1.3.5.
Line data of odd field of ..., then 2.4.6
... is supplied to the buffer 81 in the color conversion unit 61 in the "mode in which even field line data is supplied". This signal indicates R, G, B color signals and switching of one screen. A vertical synchronizing signal (1V signal), a horizontal synchronizing signal (IH double signal, clock signal, D2s mode signal, O/E signal, etc.) indicating the division of each line are supplied.Then, the first and third lines are Transcription data (RSG
, B image signals) are stored in the RAM 82 via the buffer 81. The first line image signal stored in the RAM 82 is converted into a color signal by a color conversion ROM 83 and output to the head drive circuit 62. As a result, the head drive circuit 62 prints black for one scanning line of the first line by driving the thermal head 8 in accordance with the supplied print data.

Then, when image information for one screen is supplied again, the transfer data of the second line and the fourth line are stored in the RAM 82. Then, the image signals of the second line and the third line in the image signals of the second, third, and fourth lines stored in the RAM 82 are sequentially converted into color signals by the color conversion ROM 83 and sent to the head drive circuit 62. is output to. As a result, the head drive circuit 62 drives the second and third thermal heads 8 according to the supplied print data.
Print the line in black. After that, transcription data (R, G
, B image signals) are stored in the RAM 82 for two lines. That is, for each frame, two lines of black are printed, and printing as shown in FIG. 5 is performed. In this case, the R, G, and B signals are stored in the RAM 82 in units of three lines, and each data is printed in one dot configuration.

One frame (approximately 16.
Within 7 m5), the thermal head prints two lines and takes in the next two odd or even lines of data. Then, when printing of all lines is completed, the paper P is discharged.

As described above, one line can be printed within the time required to capture one screen of data without requiring memory capacity, and printing can be performed in the minimum amount of time. Also, in interlace mode, it distinguishes between even lines and odd lines, and according to this discrimination, two lines of data are captured within the data capture time of one screen, and this captured data and the previous captured data are combined to form one screen. It is possible to print two lines within the data acquisition time, thereby shortening the printing time.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an image forming apparatus that requires less memory capacity and has a simpler circuit.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a block diagram showing a schematic configuration of a color conversion section, FIG. 2 is a diagram for explaining the configuration of one screen data, and FIGS. The diagram is D
A timing chart for explaining the operation of the main parts in the I/D2 mode, FIG. 5 is a diagram showing a printing example in the D2s mode, and FIGS. 6 and 7 are timing charts for explaining the operation of the main parts in the D2s mode. Timing chart,
8 is an external perspective view of the image forming apparatus, FIG. 9 is a sectional view showing the internal structure of FIG. 8, FIG. 10 is a perspective view showing the upper unit in an open state, and FIG. 11 is a control system. It is a block diagram. 60... Control unit, 61... Color conversion unit, 62... Head drive unit, P... Paper (transferring material), 81... Buffer, 82... RAM, 83... Color conversion ROM
, 84...Selector, 85...Intake instruction circuit, 8
6... Synchronous circuit, 87... Write dot counter, 8
8...Read dot counter.

Claims (1)

[Claims] In an image forming apparatus that forms an image by transferring the color material of the transfer material to the transfer material, there is a means for outputting image information for one screen one scanning line at a time, and a horizontal synchronization at each break of each scanning line. means for outputting a signal; means for outputting a vertical synchronization signal for each break in the image information; storage means for storing data for at least one scanning line for each horizontal synchronization signal; an image forming apparatus comprising: a transfer means for transferring one scanning line's worth of stored content onto a transfer material using the transfer material before the next vertical synchronization signal is supplied.