JPS5897059A - Adjusting device for copy density of copying machine - Google Patents

Abstract

PURPOSE:To obtain a copy with desired specific density easily by adjusting toner density and the quantity of light varying with film density. CONSTITUTION:To adjust the quantity of light transmitted through a film 2 so that the light with a prescribed level reaches a photoreceptor 6, the film 2 is placed on a scanning table and while a light source 1 is turned on, its quantity of light is measured by a sensor 5 to set the intensity of the light of the light source 1 so that the quantity of light has a prescribed value. To adjust the toner density in a developing machine 8, a lamp 11 is turned on through a light-quantity adjusting part 16 and a reference latent image is formed on the photoreceptor. This reference latent image is made into a toner image, which is measured by a density sensor 12. The adjusting part 16 receives its density signal and adjusts the supplemented amount of toner of a toner supplementing device 10. Thus, a copy with desired specific density is obtained easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for adjusting the copy density of a copying machine that uses film as an original.

In a copying machine that uses a film such as microfilm as an original, the density of a copy changes not only depending on the toner density within the machine, but also depending on the amount of exposure caused by the transmission density of the film. Conventionally, with regard to the exposure amount trap, the user operated an adjusting means such as a knob provided on the operation panel of the copying machine to open and close the diaphragm. Furthermore, the toner was adjusted by the user using a knob or the like.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a copy density adjusting device for a copying machine, which eliminates the inconvenience of the user adjusting the S light amount and toner density, and allows the user to always obtain a desired copy.

According to the present invention, the light from the light source is transmitted through the support film and the amount of light is projected onto the photoreceptor.
In a copying machine in which the image formed on the photoreceptor is replaced by toner, it is arranged to detect the amount of light that passes through the film and reaches the photoreceptor, and outputs the detected light amount signal. A light amount sensor connected to the sensor and changing the amount of light from the f source according to the amount of light reaching the photoreceptor, and a latent image at a certain level on the photoreceptor separately from the film a reference latent image forming means to form a reference latent image, a density sensor to detect the density of the reference latent image developed with toner, and a toner connected to the density sensor and provided in the current machine according to the detected density. There is provided a copy density adjusting device characterized by comprising: means for adjusting the amount of toner loss in a replenisher;
Copies with the desired density can always be obtained without being affected by the amount of light transmitted through the film, that is, the density or the density of the image.

Embodiments of the present invention will be described below with reference to the drawings.

In the drawing, an FF source 1, which is a rung, irradiates light onto a microfilm 2 placed on a film scanning table (not shown), and the light transmitted through the film forms a light source as it is supported by the film 2. , are magnified by a lens 2 and are converted into a slit-like linear light amount to a slit 4. This slit 4 is provided with a light amount sensor 5 for detecting the amount of light transmitted through the film 2, and thereby the transmission density of the film is measured.

The slit 4 is arranged very close to the drum-shaped photoreceptor 6, so that the photoreceptor 6 is exposed with an amount of light having a clear boundary. Before being exposed to light, the surface of the photoreceptor 6 is uniformly charged by a charger 7, rotated in the direction of the arrow, and exposed to light to form a latent image on the drum surface. This a
After the toner image is visualized as a toner image by the JJ1gII machine 8, the toner image is transferred to paper passing through a sieve or the like to make a copy.

After the transfer, the drum surface is cleanly discharged and uniformly charged again by the corona charger 7 to prepare for the next forming cycle.

A mixed developer consisting of toner and a medium supporting this toner is stored in the developing machine 10. During the boundary operation, the carrier is not lost, but the toner is consumed according to the area of the medium.
Therefore, a container 9 containing toner i is provided in the upper part of the AM machine 10, and a toner supply 5 is provided in the lower part of this container.
10 is attached to continuously replenish toner into the l1m machine 8.

This toner replenisher 1O may be any arbitrary device such as a rod-shaped body driven by a motor or the like, a vibrating body, or a slit whose opening area can be adjusted.

Since the image formed on the film is usually a negative image, the latent image formed on the photoreceptor has the discharged area of the photoreceptor as the base area and the undischarged area as the background area. Therefore, in the current area, with the help of the current electrode, the toner is controlled so that it adheres to the placement area, which is the discharge area, and does not adhere to the background area, which is the undischarged area (i.e., the charged area). ing.

A rung 11 is attached between the exposure section and the development section in close proximity to the photoconductor 6 for irradiating the photoconductor with a constant amount of light).
This second ring 11 forms a latent image on the photoreceptor as a nose reference according to a predetermined amount of light. This standard latent image is developed by the developing machine 8, and the density of the toner image after developing is measured by the density sensor 12 disposed downstream of the block machine 8. You can know the toner density. It is preferable to use a suitable light 1113 such as a light emitting diode for this ejection of am degree. According to this, the concentration sensor f12 can know the 4a concentration from the intensity of the reflected light from the light guide 13.

As shown in FIG. IIK, a light source 1, a light quantity set, a toner replenisher 10, a 2-powder forming means 11% purity sensor 12, and a light flIA 13 are connected to a control device 14 including a microcomputer and the like. In particular, the base thickness 1 and the light amount sensor 5 are connected to the light amount adjusting section 15 of the control device 14, and the toner replenisher 10, light fill, 1ll1 degree 7/s 12, etc. are connected to the toner loss of the control device 14. Amount adjustment section 16
It is connected to the.

In the above configuration, in order to adjust the amount of light transmitted through the film 2 to reach the photoreceptor 6 at a predetermined level, the film 2 to be copied is placed on the scanning table, and the light source 1 is set to an arbitrary intensity. The light quantity is measured by the CEF v5 and the light quantity is manually inputted to the light quantity adjustment section 15. Based on the data, the micro combinator 17 calculates the intensity of ft and the source l according to the 7'o data, and adjusts the intensity of the light #ll so that the amount of light irradiated to the photoreceptor Ic becomes a predetermined value. Set it as follows.

The light amount sensor 5 measures the background part of the film.
Preferably, the light intensity adjustment unit 15 of the control device 14 selects a small internal value (background part in my case) of the output of these sensors, and based on this minimum value, According to a calculation formula set in the microcomputer 17, the voltage of the light source can be adjusted so that the photoreceptor is exposed with an amount of light corresponding to the film density.

To adjust the toner density in the current dispensing machine 8, light intensity! 111
! The rungs 11 to 16 are turned on. In this case, it is preferable to turn off the light source 1. However, the rung 11 can be arranged so as to irradiate an area other than the image forming area on the photoreceptor, and can be blocked so that the light from the source a1 does not enter that area. In this case, there is no need to turn off the light source 1, and there is an advantage that the toner density can be measured even during image formation. The lamp 11 is turned on for a certain period of time, and a standard solid area of a certain length is formed on the photoreceptor. This reference a image is agglomerated into toner* by the Fi developing device 8, and when this placed portion reaches the position of the density sensor 12, ft and a13 are lit and the intensity of the reflected light is measured by the density sensor t12.

The toner density adjustment section 16 receives the measured density signal. If the level is high, there is less toner, so a signal is given to increase the amount of toner delivered to the toner replenisher '10VC, and if the level is small, there is more toner. gives a signal to the toner replenisher 10 to reduce the amount of toner dispensed. The determination of the magnitude of this concentration level is performed by the micro combinator 17.

As mentioned above, since the amount of light caused by the film density and the toner density in the current machine, which affect the copy density, can be adjusted independently, these ms can be adjusted very easily, and each pixel can be adjusted independently.
With A1!1 copy it is possible to obtain copies of the desired constant density. In particular, in this embodiment, the light intensity is adjusted after the film is placed on the scanning table, and after copying is completed, the film projection light source is turned off and the amount of toner is detected to avoid wastage of toner during the next copying operation. If the amount is adjusted, the time delay for adjustment will have little effect. Of course, as mentioned above, by arranging the lamp serving as the latent image forming means in an area other than the image forming area of the photoreceptor, image formation and toner density adjustment can be performed in parallel, further shortening the adjustment time. can do.

Although the above-mentioned embodiments have been explained using negative films, the present invention can be applied to I-di films as well. In this case, the reference latent image forming means u/f can be replaced with any fII form acid forming means such as a rung with a light-shielding plate or a charger. Also, if multiple light intensity sensors are used, the maximum value is selected. Just do it.

Furthermore, although the amount of light is adjusted by controlling the rung voltage in the embodiment described above, it is also possible to use any other known means such as controlling the diaphragm or slit width.

Furthermore, it is possible to use a microcomputer to determine whether the toner concentration is excessive or insufficient based on the density signal of the reference latent flaw, and display the status to the operator. It is also possible to display

[Brief explanation of the drawing]

The drawing is an explanatory diagram showing a copy density adjusting device for a copying machine which is an embodiment of the present invention. l...5tfl, 2...film, 4...slit, 5...light intensity se/f16...photoreceptor, 7...charger, 8...ll moat machine, 9...・Toner container, 10・
... Toner supply device, 11 ... Rung for standard latent scratch formation,
DESCRIPTION OF SYMBOLS 12... Density sensor, 13... Light source, 14 Control device, 15... Light amount tA pot part, 16... Toner density adjustment part

Claims (1)

[Claims] The light from the light source passes through the film that supported me, and the 'f
In a copying machine in which the latent image formed on the photoreceptor is projected onto the photoreceptor by toner, the latent image passes through the film and reaches the photoreceptor. A light amount sensor arranged to detect the amount of light and outputting a detected light amount signal; a light amount adjusting means connected to the photoreceptor and changing the intensity of the light source according to the amount of light reaching the photoreceptor; a reference latent image forming means for forming a latent image of a certain level on the surface of the photoreceptor separately from the film image; and a reference latent image forming means connected to the toner. A density sensor that detects the toner density of the reference latent image that has been developed, and means that is connected to the density sensor and adjusts the amount of toner dispensed from a toner replenisher provided in the iA wingman according to the detected density. A copy density adjustment device characterized by: