JPS59189365A - Scanning exposure device of color copying machine - Google Patents

Abstract

PURPOSE:To improve the copy speed of color copying by using plural light sources which have different spectral characteristics and scanning and exposing an original to be copied. CONSTITUTION:A platen carriage 7 is provided movably on a rail 6 laid in the scanning direction of the original 5 to be copied under a platen 4 mounting the original 5, and light sources 1, 2, and 3 are fitted to the lamp carriage 7 through a bearing 21. The light source 1 with main wavelength corresponding to blue is at the position facing the original 5 when the copying starts, and the original 5 is irradiated by this light source 1 once the copying starts to expose the surface of a photosensitive body 17 to light with the main wavelength corresponding to blue through an optical system. When the lamp carriage 7 reaching a return end returns to its home position 9, a lamp support body 22 is rotated by 120 deg. by a rotation driving source 24 during said period and the light source 2 having main wavelength corresponding to green stops facing the original 5. Then, the original 5 is scanned and exposed by the light source 2 through a carriage driving system. Similarly, scanning exposure by the light source with principal wavelength corresponding to red is carried out to obtain one color copy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a scanning exposure device for a color copying machine that scans and exposes an original to be copied using a plurality of light sources having different spectral characteristics.

Prior Art Conventional color copying machines that repeat exposure, development, and transfer multiple times for each color use a halogen lamp as a light source as shown in Figure 1 (a), and a fluorescent lamp as shown in Figure 1 (b). The one used is known.

In the device using the halogen lamp α shown in FIG. 1(A), the light emitted from the halogen lamp α is reflected.

C to the document C on the platen d, and the reflected light from the document e is guided to a photoreceptor (not shown) via a color separation filter f. Multiple color separation filters f are prepared. By using these alternately, the second
As shown in Figure (A), each color is separated and the photoreceptor is exposed for each color.

Also, the fluorescent lamp shown in Figure 1 (b)! In the case of using I, a fluorescent lamp is used to illuminate an original e on a sifting platen d, and the reflected light is passed alternately through a plurality of color separation filters f and guided to a photoreceptor, thereby exposing the photoreceptor. ing.

This type of exposure equipment requires about three times the amount of light compared to black and white copying, so if a halogen lamp α is used as the light source, the lamp consumption will be large, resulting in an increase in the power consumption of the entire copying machine. In addition, when a fluorescent lamp is used as a light source, the amount of light is insufficient, so the exposure speed must be slowed down, resulting in a reduction in copying speed.

OBJECT OF THE INVENTION The present invention has been made to improve the above drawbacks, and provides a scanning exposure device for a color copying machine that scans and exposes an original to be copied by alternately using a plurality of light sources with different spectral characteristics. The aim is to reduce power consumption and improve copying speed.

Structure of the Invention A lamp carriage is provided below the platen on which the original to be copied is placed, so as to be movable in the scanning direction of the original, and a plurality of light sources with different spectral characteristics are bundled on this rung carriage so as to be rotatable. This is a scanning exposure device for a color copying machine in which a light source is rotated and turned on each time the lamp carriage moves back and forth, and each light source scans and exposes an original to be copied.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings shown in FIG. 3 and below.

Figure 3 shows the 1°2.30 spectral characteristics of three light sources used in this invention, where light source 1 is a fluorescent lamp with blue as its main wavelength, and light source 2 is a fluorescent lamp with green as its main wavelength. , and a light source 31d is a fluorescent lamp whose main wavelength is red, and these light sources 1.2.3 are provided below the platen 4 in the following arrangement as shown in FIG. That is, 7 is a lamp carriage, which is movably provided on a rail 6 installed along the scanning direction of the original 5 below the platen 4 on which the original 5 to be copied is placed. A rotating shaft 22α of the lamp support 22 is supported via 21. The supports 22 are disc-shaped and spaced apart from each other, and the light sources 1, 2.3 are installed between these lamp supports 22.

These light sources 1, 2.3 are arranged at equal intervals on a circumference centered on the center 0 of a rotating shaft 22α, and a gear 23 attached to the rotating shaft 22α is connected to a rotary drive source 24 consisting of a step motor. The rotational drive source 24 drives each light source 1,
2.3 is rotated intermittently.

Further, the lamp carriage 7 is connected to a carriage drive system (not shown) via a wire 8, and is reciprocated along the rail 6 by this carriage drive system in the following manner.

At the start of copying, a light source 1 having a dominant wavelength of blue is located at a position facing the original 5 to be copied, as shown in FIG. 4, and the original 5 is irradiated by this light source 1 at the same time as the start of copying. The reflected light from the original 5 is refracted toward the second mirror 12 by the first mirror 11 provided on the lamp carriage 7 .

The second mirror 12 is attached together with the third mirror 14 to a mirror carriage 13 that moves in the same direction at the same speed as the lamp carriage of the first mirror 11, and the reflected light from the first mirror 11 is reflected from the second mirror 11. It is refracted toward the lens 15 by the third mirror 13,14. The light that has reached the lens 15 passes through it and reaches the fixed mirror 16, where it is refracted toward the photoreceptor 17, and the surface of the photoreceptor 17 is exposed to light from the light source 1 whose main wavelength is blue. be done. The electrostatic latent image formed on the surface of the photoreceptor 17 is transferred to the paper through a developing process, and the lamp carriage 7 reaches the return end.
returns to home position 9 at a faster speed than on the outward journey.

Meanwhile, the lamp support 22 is rotated by the rotational drive source 24.
When the lamp carriage 7 reaches the home position 9 after being rotated by 0°, the light source 2 whose main wavelength is green is stopped at a position facing the original 5. Thereafter, the lamp carriage 7 is again moved in the forward direction by the carriage drive system, and the original 5 is scanned and exposed by the light source 2. Similar to the j-th exposure, the reflected light from the original 5 travels along a 2° optical path connecting the first mirror 11 and the photoreceptor 17 to the photoreceptor 17.
The photoreceptor 17 is exposed to reflected light from the light source 2 whose main wavelength is green. The electrostatic latent image formed by this exposure goes through a developing process and is transferred again to the paper onto which it was transferred in the first process, and the lamp carriage 7 that has reached the return end moves to the home position 9 at a faster speed than the forward path. During this period, the rung support 22 is rotated 1200 times by the rotation 1 drive source 24, and when the lamp carriage 7 reaches the home position 9, the light source 3 with all the red dominant wavelengths is at the position facing the original 5. becomes. Thereafter, the lamp carriage 7 is moved in the forward direction again, the light source 3 performs the third scanning exposure, and the first... Similar to the second time, an electrostatic latent image is formed on the photoreceptor 17, and after this image is developed, the first image is developed. It has been transferred to the paper that was transferred the second time. Further, the lamp carriage 7 that has reached the return end is returned to the home position 9 at a faster speed than the forward journey, and one copy cycle is completed, and one color copy can be obtained.

Effects of the Invention As described in detail above, the present invention rotates a plurality of light sources with different spectral characteristics each time an original to be copied is scanned, and each light source scans and exposes the original. It is possible to reduce the power consumption to an almost unprecedented level compared to the one using a halogen lamp as the light source, and it is also possible to significantly improve the copying speed compared to the one using a white fluorescent lamp as the light source.

Furthermore, since there is no need to switch between multiple spectral filters, the apparatus can be simplified.

[Brief explanation of drawings]

FIG. 1 (A I, F) is an explanatory diagram of a conventional scanning exposure device;
Figures 2 (a) and (b) are explanatory diagrams showing the same spectral characteristics, and Figure 3
The figure is a diagram showing the dominant wavelength of the light source used in an embodiment of the present invention, FIG. 4 is a block diagram of the same scanning exposure apparatus, and FIG. 5 is a detailed diagram of the light source rotating section. 1.2.3 is a light source, 4 is a platen, and 5 is a document. 7 is a lamp carriage. (>3)

Claims (1)

[Claims] A lamp carriage 7 is provided below the platen 4 on which the original 5 to be copied is placed, and is movable in the scanning direction of the original 5.
A plurality of light sources 1, 2.3 having different spectral characteristics are installed in a bundle on this lamp carriage 7, and these light sources 1, 2.
, 2.3 are rotated and turned on each time the lamp carriage 7 reciprocates, and each light source 1, 2.3 scans and exposes an original 5 to be copied.