JPH07115528B2 - Recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device such as a laser beam printer, and more particularly to a test print of a recording device in which a plurality of kinds of paper sizes are set as printable paper. It is a thing.

[Conventional technology]

FIG. 4 is a diagram for explaining the image forming operation of the conventional laser beam printer, and 21 is an image signal (VDO) which is input to the laser unit 22. 23 is a laser beam which is on / off modulated by the laser unit 22, 24 is a motor,
The rotary polygon mirror (polygon mirror) 25 is rotated at a constant speed. 26
Is an imaging lens for focusing the deflected laser beam 27 on the photosensitive drum 28. Therefore, the laser beam 27 modulated by the image signal 21 is horizontally scanned (scanning in the main scanning direction) on the photosensitive drum 28. Reference numeral 29 denotes a beam detector, which is composed of a photoelectric conversion element 30, for example, a photodiode, and outputs a beam position right birth number (BD signal) 31 which becomes image writing timing. Reference numeral 32 denotes a transfer paper, which visualizes a latent image formed on the photoconductor by a developing device (not shown), and a developer (toner) is transferred by the transfer device (not shown).

Next, the operation of each unit will be described.

The laser unit 22 generates a laser beam 23 that is modulated based on the input image signal 21. The VDO 21 is generated by a control unit (not shown) inside the laser beam printer.
The modulated laser beam 23 enters a polygon mirror 25 having a plurality of mirror surfaces driven by a motor 24 and is deflected in the horizontal direction. When the polygon mirror 25 rotates at a constant speed, the deflected laser beam 27 scans the photosensitive drum 28 at a constant speed. Further, the laser beam 27 is focused on the photosensitive drum 28 by the imaging lens 26. When the photosensitive drum 28 rotates at a constant speed and the laser beam 27 scans at a constant speed, a latent image based on the VDO signal 21 is formed on the photosensitive drum 28. At this time, the laser beam 27 is incident on the photoelectric conversion element 30 of the beam detector 29 fixed near the scanning start position, and the BD signal 31 is generated. The BD signal 31 is sent to the control device of the printer unit described above. BD signal 31 is
It is generated at a constant cycle for each scanning of the laser beam 27. The control device synchronizes with the BD signal 31 and VDO signal 21 for one scan
Is generated to define the image position on the photosensitive drum 28 in the main scanning direction.

FIG. 5 is a timing chart showing the relationship between the VDO signal 21 and the BD signal 31, and the same components as those in FIG. 4 are designated by the same reference numerals.

As can be seen from this figure, after the beam detector 29 detects the BD signal 31, a VDO signal 21 (hatched portion) is generated after a fixed time T (s). In the figure, two scans are shown.

As described above, the latent image formed on the photosensitive drum 28 is visualized by a known electrophotographic process and then transferred and fixed on the transfer paper 32 to obtain a hard copy. Also, transfer paper
As the 32, plain paper of a normal standard size (for example, A3, A4, B5, etc.) is used, and the paper size that can be passed is set from several types to ten types according to the specifications of the printer.

The laser beam printer has a test pattern generation circuit for generating a test pattern for checking whether the electrophotographic process is normal (whether or not an image is output) and whether the paper transport system is normal. In this case, conventionally, the effective image area is adjusted according to the size of the paper that is passed through the print area, and no matter what size paper that is set in the printer specifications is passed, the entire effective image area of that paper is passed. The test pattern was printed on. Further, the test pattern to be printed is in consideration of a certain degree of image evaluation such as a character pattern by a content character generator or a lattice pattern. Further, if the image area is made to extend beyond the paper sheet without adjusting the print area, there is a risk that untransferred toner may stain the charger.

[Problems to be solved by the invention]

Therefore, the test pattern generation circuit requires a circuit for limiting the image area for each paper size to be passed and a high-speed processing circuit for outputting an image that changes in the main scanning direction, which is considerably complicated and costly. There was a problem that it became a thing.

It is expected that the price of laser beam printers will be reduced in the future, and it is strongly desired to develop a device that has a simple circuit configuration and can perform test printing capable of performing necessary and sufficient functions.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a small-sized and inexpensive recording apparatus having a simple circuit configuration and capable of performing necessary and sufficient test prints.

[Means for solving problems]

The recording apparatus according to the present invention has a test pattern generating means for generating a test pattern at the time of test printing, and a recording means for recording the test pattern generated by the test pattern generating means using an electrostatic recording method, The test pattern generating means generates a constant test pattern in which the effective image area in the main scanning direction is within the range of the minimum paper size that can be used in the recording apparatus regardless of the paper size of the recording paper to be printed. It is configured in.

[Action]

According to the present invention, during the test printing, the effective image area in the main scanning direction is constant within the range of the minimum paper size that can be used by the printing apparatus, regardless of the paper size of the printing paper to be printed by the test pattern generating means. The test pattern is generated, and the recording means records the test pattern using the electrostatic recording method, so that it is possible to perform the test print independent of the paper size.

〔Example〕

FIG. 1 is a schematic view showing an example of a test print output of a laser beam printer showing an embodiment of the present invention.
Is A3 size transfer paper, for example, in the arrow direction (sub-scanning direction)
Be transported to. However, all are vertically fed, that is, the shorter side of the paper is the main scanning direction. Reference numeral 2 is a paper size area line showing A4 size, 3 is a paper size area line showing A5 size, and 4 is a top margin of the transfer paper 1, for example, a mm. Reference numeral 5 is a left margin, for example, b mm. 6 is a test pattern (indicated by a horizontal line),
The test pattern is printed at a constant test pattern interval 7, for example, d mm, and is printed on the effective image area in the main scanning direction of A5 size (minimum paper size set in specifications) of the A3 size transfer paper 1. It is in a state of being.

As can be seen from this figure, since the printing (effective image) area in the main scanning direction is fixed to A5 size (minimum size), the photosensitive drum 28 can be used regardless of the size of paper allowed in the specifications. Since the upper toner image does not exceed the paper width in the main scanning direction, it is possible to prevent dirt inside the printer and waste of toner. Also, top margin 4, left margin 5
If the values are always a and b mm, respectively, it is possible to detect an abnormality in the paper feed timing and an abnormality in the lateral resist.
With d mm (constant), it is possible to detect abnormalities such as uneven speed of paper transport.

FIG. 2 is a test pattern generation circuit diagram of a laser beam printer showing an embodiment of the present invention, and 11 is an oscillator,
A clock signal CK of several MHz is generated. Reference numerals 12 and 13 are counters that count the clock signal CK. Note that the counter
12, 13 function as timers reset by the BD signal 31. 14 Gate array H that determines the effective image area
In order to generate the -LIMT signal 17, the H-STAT signal 15a and the H-END signal 15b are connected to the JK flip-flop (JKFF) 16 J
Output to the terminal and K terminal. JKFF16 is H-STAT signal 15
The H-LIMT signal 17 (which determines the image area in the main scanning direction) is output to the gate array 18 in synchronization with a and the H-END signal 15b. The gate array 18 uses the test pattern TV according to the count value of the BD signal 31 counted by the counters 19a and 19b.
The DO is output to the laser unit 22. A V-LIMT signal 20 determines the image area in the sub-scanning direction. V-LIMT signal 20
Is generated using, for example, a timer of a microcomputer that controls the printer. CLR is a clear signal that clears the count of the BD signal 31.

In the recording apparatus configured as described above, at the time of test printing, the test pattern generating means generates the test pattern TVDO in which the effective image area in the main scanning direction is constant regardless of the paper size of the recording paper to be recorded. Test pattern
By recording TVDO on the transfer paper by the printer, test printing is performed regardless of the transfer paper size.

Next, the operation of FIG. 2 will be described with reference to FIG.

FIG. 3 is a timing chart for explaining the operation of FIG. 2, and the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals.

The clock signal CK oscillated from the oscillator 11 is the counter 12,1
The count value is counted at 3, and the count value is output to the subsequent gate array 14. The gate array 14 includes a beam detector 29.
When the laser beam 27 reaches the image writing position in the main scanning direction, H becomes a print prohibition release signal in the main scanning direction.
-The STAT signal 15a is output, and the laser beam 27
H-END signal 1 that becomes a print inhibit signal in the main scanning direction when the right edge of the effective image area of the size (minimum set size) is reached
Output 5b to JKFF16 J, K pins. In response to this, JKFF16
Is an H-LIMT signal 17 that determines the effective image area in the main scanning direction.
To the gate array 18.

On the other hand, the BD signals 31 are counted by the counters 19a and 19b,
The count value of the BD signal 31 is input to the gate array 18. Since one count of the BD signal 31 corresponds to one main scanning line, in the gate array 18, the BD signal 31 is tested from the Nth count to the N + 2th test pattern TVDO.
Is set to TRUE and a gate is assembled so as to output the clear signal CLR from the N + 2th count, horizontal lines of two main scanning lines (shown in FIG. 1) are obtained at intervals of N lines. FIG. 3 shows a case where the test pattern TVDO of 2 lines is output at intervals of 6 lines.

Further, since the V-LIMT signal 20 and the H-LIMT signal 17 are input to the gate array 18, if either of the signals is FALSE, the test pattern TVDO is set to FALSE, as shown in FIG. The left margin 5 and the top margin 4 can be formed at predetermined intervals. Further, when the V-LIMT signal 20 is FALSE, the clear signal CLR is always set to TRUE, so that the top margin 4 can always be made constant.

In the above embodiment, the test pattern TVDO is set to N for the sake of explanation.
The case where two lines are drawn for each line has been described, but the actual test pattern interval 7 is set to 70 to 80 lines. Further, in the above embodiment, the laser beam printer has been described as an example, but the present invention is not limited to the laser beam printer and can be applied to other recording devices such as an inkjet printer and a thermal printer.

〔The invention's effect〕

As described above, according to the present invention, at the time of test printing, the effective image area in the main scanning direction is the smallest usable in the recording apparatus regardless of the paper size of the recording paper to be recorded by the test pattern generating means. Since a constant test pattern within the range of paper size is generated, effective test print processing can be executed by generating only one test pattern even if the recording paper size is different.

Therefore, the same test print sequence does not affect the size of the recording paper, and even when recording is performed by the electrostatic recording method, it is possible to prevent the back stain and the contamination of the charger due to the transfer toner. Further, the test print control mechanism can be greatly simplified as compared with the conventional one, and an excellent effect such as inexpensive test print processing can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a test print output of a laser beam printer showing an embodiment of the present invention, and FIG. 2 is a test pattern generation circuit diagram of a laser beam printer showing an embodiment of the present invention. FIG. 4 is a timing chart for explaining the operation of FIG. 2, FIG. 4 is a diagram for explaining the image forming operation of the conventional laser beam printer, and FIG. 5 is a timing chart showing the relationship between the image signal and the beam position detection signal. is there. In the figure, 1 is a transfer paper, 2 and 3 are paper size areas, 4 is a top margin, 5 is a left margin, 6 is a test pattern, and 7
Is a test pattern interval, 11 is an oscillator, 12 and 13 are counters, 14 is a gate array, 15a is H-STAT signal, and 15b is H-.
END signal, 16 JKFF, 17 H-LIMT signal, 18 gate array, 19a, 19b counter, 20 V-LIMT signal, 21 image signal, 31 BD signal, CK clock signal, CLR clear Signal, TVDO is a test pattern.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yukihide Ushio 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshio Yoshimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Kya Non-Corporation (56) Reference JP-A-58-116185 (JP, A)

Claims (1)

[Claims] 1. In a recording apparatus capable of forming an image on recording paper of a plurality of paper sizes, a test pattern generating means for generating a test pattern during test printing and a test pattern generated by the test pattern generating means are electrostatically charged. Recording means for recording using a recording method, wherein the test pattern generating means has a minimum effective image area in the main scanning direction that can be used in the recording device regardless of the paper size of the recording paper to be recorded. A recording apparatus configured to generate a constant test pattern within a paper size range.