JPS6172266A - Print quality judging device - Google Patents

Abstract

PURPOSE:To confirm accurately and automatically position printing and density by providing a beltlike pattern formed on a photosensitive drum and printing paper, and a reading head mechanism that reads the pattern. CONSTITUTION:A pair of reading heads are provided in a reading head mechanism 20, and a beltlike pattern developed on the face of a photosensitive drum 2 and a beltlike pattern 14 transferred a photosensitive drum 2 and a beltlike pattern 14 transferred on a printing paper 6 are read separately. When reading the pattern formed on the photosensitive drum 2 by a drum face reading circuit 16, it is necessary to stop transferring cycle to the paper 6. The reading head mechanism 20 consists of a motor 11 for driving reading head, head driving shaft 12 and a reading head 13, and controlled by a reading head driving and controlling section 15. The reading head 13 is shifted in the direction of arrow mark B-B' perpendicular to the carrying direction of the printing paper by the head driving shaft 12 that rotates in the direction of arrow mark C-C' driven by the reading head driving motor 11, and detects the position of the beltlike pattern 14.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to improvement of non-impact printer devices such as laser printers, and in particular, to the improvement of non-impact printer devices such as laser printers, and in particular, to the improvement of non-impact printer devices such as laser printers. The present invention relates to a quality determination device.

In non-impact printers using laser beams, in order to ensure printing quality performance, efforts are being made to improve the quality level of each unit that makes up the printing process.

However, when it comes to the overall quality level of the device, the assembly accuracy during unit combination and the influence of internal temperature rise during device operation appear as variations and displacements in print width and print position.

These problems become more noticeable when using paper with a preprinted printing frame, and are often pointed out by users because they are noticeable even when the amount of fluctuation is extremely small.

On the other hand, as a provider of equipment, these printing widths are important.

When checking the printing position, etc., it is not enough to just check the pattern printed on the printing paper; it is necessary to compare both the pattern developed on the photosensitive drum and the pattern immediately after being transferred to the paper with the "absolute position". Therefore, it is important to confirm which side is at fault and take corrective action.

However, directly measuring the development width on the surface of the photosensitive drum is practically difficult due to the risk of damaging the drum itself and low workability.

Therefore, there is a strong demand for the development of a print quality determination device that can automatically measure and confirm the entire printing process with high precision and in a short time.

C. Prior Art FIG. 2 is a diagram for explaining the configuration of a conventional non-impact printer device, in which (a) is a side sectional view of the main part, and (f) is a side sectional view of the main part.
bl is a front view of main parts.

As shown in FIG. Transfer mechanism 5 provided at opposing positions
and a paper transport mechanism 8 that transports printing paper 6 placed between the transfer mechanism 5 and the photosensitive drum 2 in the direction of arrow A at a predetermined speed.

The photosensitive drum 2, which rotates in the direction of arrow C, is given a high potential by the charger 1, and the latent image formed on the outer surface by the laser beam 3 is visualized by the developing device 4 (hereinafter referred to as development). It has become.

Note that the developed image is pressed onto the printing paper 6 that is conveyed in the direction of arrow A on the transfer mechanism 5 and is transferred onto the paper 6.

However, in the case of the above-mentioned conventional structure, as shown in FIG. 6(b), it is sufficient that the characters printed in the printing area 7 of the printing paper 6 are recorded at the correct position, but due to the reasons mentioned above, the recorded character position is not correct. may not exactly match the left end 6B of the print area or the right end 6C of the print area of the printing paper 6.

This phenomenon occurs when a printing frame 6° is preprinted within the printing area 7, and the characters “extrude” outside the printing frame 6°, which is unsightly and significantly impairs printing quality. .

However, since the factors that cause the above phenomenon are complex, it is not easy to pursue them, and the conventional inspection method was to make adjustments half-heartedly while printing on printing paper. and wasting inspection time.

Note that in the same figure (IO in BL indicates the device frame, and 6A indicates the reference edge of the paper.

[Problem that the invention seeks to solve]

The present invention provides a print quality determination device configured to be able to check minute fluctuations in print width and print position, which have been difficult to elucidate using conventional inspection methods, separately for the photosensitive drum side and the printing paper side. It was made for the purpose of

[Means for solving problems]

The above-mentioned problem lies in a print quality determination device for a non-impact printer that develops a latent image formed on a photosensitive drum and transfers it to printing paper. The structure includes a strip pattern and a reading head mechanism that measures the position of the strip pattern, the strip pattern is formed such that its longitudinal direction is perpendicular to the conveying direction of the printing paper, and the reading head mechanism The problem is solved by a print quality determination device comprising at least a pair of reading heads that detect the position of the strip pattern formed on the photosensitive drum and the printing paper.

[Effect]

The present invention forms a band-like pattern that pseudo-represents the actual position where printing is performed on the photosensitive drum and printing paper, respectively, and determines the formation position of the band-like pattern and each reference printing position on the photosensitive drum and the printing paper. The configuration is such that the printing position error and its occurrence location can be confirmed by comparing the two.

〔Example〕

FIG. 1 is a diagram for explaining an embodiment of a non-impact type printer according to the present invention, in which (al) shows a side sectional view and block diagram of the main part, and (b) shows a front view of the main part. However, the same reference numerals indicate the same objects throughout the figures.

The printer device of the present invention includes a reading head mechanism 20 equipped with a pair of reading heads 13 connected to a drum surface reading circuit section 16 and a paper surface reading circuit section 17, respectively, as shown in FIG. The present invention is characterized in that it is provided with a band-like pattern forming section (not shown) that forms a band-like pattern 14 based on the above on the photosensitive drum 2 and printing paper 6.

The reading head mechanism 20 is equipped with a pair of reading heads 13, and is structured to be able to read separately the strip pattern 14 developed on the surface of the photosensitive drum 2 and the same strip pattern 14 transferred onto the printing paper 6. ing.

If the pattern formed on the photosensitive drum 2 is to be read by the drum surface reading circuit section 16, the transfer cycle to the paper 6 needs to be stopped.

The reading head mechanism 20 includes a reading head driving motor 11, a head driving shaft 12, and a reading head 13, and is controlled by a reading head driving control section 15.

The reading head 13 is driven by a reading head driving motor 11 and rotates in the direction of arrow c-c'.
2, the arrow B-B is perpendicular to the conveyance direction of the printing paper 6.
' direction and detects the position of the strip pattern 14 as shown in FIG.

In order to make the explanation easier to understand, the reading head 13 in the figure is limited to reading the paper surface.

The left end 14B and right end 14C of the strip pattern 14 are
The position is set at a constant ratio to the paper reference edge 6^, the left edge 6B of the printing area, and the right edge 6C of the printing area when the printing paper 6 is in the normal position (reference position).

Therefore, when the reading head 13 confirms the position of the strip pattern 14, the frame reference end 14 is automatically
The distance l from A to the left edge 14B of the strip pattern and the distance from the right edge 14C of the strip pattern are calculated, and compared with the nominal L/l value manually input to the comparator 18, the amount of displacement is calculated. Ru.

Note that a display circuit section and a correction circuit section are connected to the subsequent stage of the comparator 18 in order to improve the efficiency of adjustment work.

In the present invention, the developed strip pattern 14 is read by the drum surface reading circuit section 16, and the transferred strip pattern is read by the paper surface reading circuit section 17, and compared with the preset L/N nominal value to determine whether it is good or bad. It is for making judgments.

Further, the dimensional difference in the position displayed on the display circuit of the comparator 18 may be fed back to a circuit and mechanism that corrects it within the allowable dimensions.

Note that the strip pattern 14 is provided for off-line testing, but in order to check the printing density over the entire pattern, it may be formed into a "hetero black" pattern and a wide pattern.

[Effects of the Invention] As described above in detail, the print quality determination device of the present invention uses a strip pattern formed on a photosensitive drum and printing paper and a reading head mechanism to read the strip pattern to determine the print position and print quality. This has a great effect in that the concentration can be accurately and automatically confirmed.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining an embodiment of a non-invacuum type printer according to the present invention, in which (al is a side sectional view and block diagram of main parts, (bl is a front view of main parts, and FIG. 1 is a diagram for explaining the configuration of a conventional non-impact printer device, (al is a side sectional view of the main part, and (bl is a front view of the main part. In the figure, 1 is a charger, 2 is a photosensitive drum. , 3 is a laser beam, 4 is a developer, 5 is a transfer mechanism, 6 is printing paper, 6A is a paper reference edge, 6B is the left end of the print area, 6C is the right end of the print area,
7 is a print area, 8 is a paper transport mechanism, 10 is an apparatus frame, IOA is a frame reference end, 11 is a reading head drive motor, 12 is a head drive shaft, 13 is a reading head, 14 is a strip pattern, 14B is a strip pattern The left end, 14G, is the right end of the strip pattern, 15 is a reading head drive control section, 16 is a drum surface reading circuit section, 17 is a paper surface reading circuit section, 18 is a comparator, and 20 is a reading head mechanism. 1st Flash (b) Figure 2 (Q) (b) A

Claims (1)

[Claims] A print quality determination device for a non-impact printer that develops a latent image formed on a photosensitive drum and transfers it to printing paper, the device being used to detect a band-like pattern formed on the photosensitive drum and the printing paper, The configuration includes a reading head mechanism that measures the position of the strip pattern, the strip pattern is formed such that the longitudinal direction is perpendicular to the conveying direction of the printing paper, and the reading head mechanism is configured to measure the position of the strip pattern. A print quality determination device comprising at least a pair of reading heads that detect the position of the strip pattern formed on a sheet of paper.