JPH0442673B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] In order to reduce power consumption during exposure and improve exposure speed, the present invention provides a plurality of light sources with different spectral characteristics below the platen, and uses a light source that is determined in advance. The present invention relates to a scanning exposure device for a color copying machine that performs scanning exposure in the same order.

[Prior art]

As a conventional scanning exposure device for a color copying machine, there is one shown in FIGS. 1 and 2, for example. 1st
The device shown in the figure is a platen 2 on which a document 1 is placed.
, a halogen lamp 3 that emits light from the bottom of the platen 2, a reflector 4 that guides the light emitted by the halogen lamp 3 to the document surface, and a reflector 5 that re-reflects the light reflected by the platen 2 toward the document side. , a plurality of color separation filters 6 that color-separate the reflected light from the original 1 and pass the light, and a photoreceptor 7 that passes the light from the color separation filters 6 to
An optical system 8 forms an image on the photosensitive layer to form an electrostatic latent image on the photosensitive layer.

In the above configuration, when the copy start button is operated, the platen 2 on which the original is placed moves in one direction, and in the process of this movement, the halogen lamp 3 illuminates a part of the original (perpendicular to the traveling direction). fixed width) are sequentially irradiated. As the document 1 moves, that is, as it scans, the reflected light from the light irradiation surface is color-separated by a single filter 6 placed in the optical path, and then imaged on the photoreceptor 7, as shown in FIG. hand,
An electrostatic latent image of the specified color is formed by the filter 6. By developing this electrostatic latent image with a corresponding color toner, it is possible to transfer one color. The above operations are performed for each of the filters 6, for example, red, green, and blue.
Color printing can be done by following the colors and overlapping the colors.

The apparatus shown in FIG. 2 is an example in which a fluorescent lamp 9 is used as a light source instead of the halogen lamp shown in FIG.
In this configuration, the document 1 on the platen 2 is irradiated by the fluorescent lamp 9, and the reflected light is sequentially applied to the three color separation filters 6 having the characteristics shown in FIG. An electrostatic latent image of each color is formed on the photoreceptor 7 while passing through the photoreceptor 7.

However, in the scanning exposure device of conventional color copying machines, the former device uses a halogen lamp as a light source, and it must be able to obtain about three times the amount of light compared to black and white copying, so lamp consumption is reduced. As a result, the power consumption of the entire copying machine may increase.Also, in the latter device, the amount of light is insufficient, so it is necessary to slow down the exposure speed to compensate for the insufficient amount of light, and as a result, the copying speed decreases. There was a fear that this could lead to a decline in

[Object and structure of the invention]

The present invention has been made in view of the above,
In order to reduce power consumption and increase exposure speed, multiple light sources with different spectral characteristics are arranged below the platen, and these light sources are lit in the order in which they are arranged to perform scanning exposure, and scanning exposure is performed for two or more cycles. The present invention provides a scanning exposure device for a color copying machine in which the scanning exposure speed is further increased by alternately lighting up the light sources in the reverse order.

〔Example〕

Hereinafter, a scanning exposure device for a color copying machine according to the present invention will be explained in detail.

FIG. 4 shows an embodiment of the present invention, and the same parts as in FIG. 1 are indicated by the same reference numbers, so redundant explanation will be omitted. A light source 11 using fluorescent lamps arranged at regular intervals in the scanning direction under a fixedly installed platen 2 and each having different spectral characteristics;
12 and 13, and a rail 14 disposed below the light sources 11, 12, and 13 along the scanning direction of the original.
, a lamp carriage 15 on which the light sources 11, 12, and 13 are fixedly installed and moves on the rail 14; and a wire 16 that moves the lamp carriage 15 in the platen scanning direction at a predetermined time using a carriage drive system (not shown) as a drive source. , a mirror 17 that reflects reflected light in a predetermined direction according to the content of the document 1 irradiated by any one of the light sources 11, 12, and 13; a mirror carriage 18 that moves with
and a mirror carriage 20 that moves in the same direction as the mirror carriage 18 at 1/2 the speed of the mirror carriage 18 with the mirror 19 fixedly installed; Mirror 21 that reflects in the right angle direction and Mirror 2
A lens 22 forms an image of the light from the original 1 at a predetermined distance position, a mirror 23 reflects the light from the lens 22 in a predetermined direction, and the scanning content of the original 1 is transferred to the surface by the lens through the mirror 23. It is composed of a photosensitive drum 24 on which an electrostatic latent image is formed by forming an image on a layer, and on which development and transfer are performed by a developing device and a transfer device (not shown).

The light sources 11, 12, and 13 have spectral characteristics as shown in FIG. Fluorescent lamps with dominant wavelengths are used in each case.

In the above configuration, when the copy start button is operated, the blue light source 11 moves from the home position 25 to the lamp carriage 1.
5 starts moving by turning on only the light source 11, and the document 1 is scanned and exposed. The reflected light from the original 1 is reflected at right angles by a mirror 17 installed on a mirror carriage 18 that moves at the same speed as the lamp carriage 15, and this reflected light is 1/2
The reflected light from the mirror 19 is further reflected by the mirror 21 and sent to the lens 22. The light from the lens 22 is reflected by the fixed mirror 23 and formed into an image on the surface of the photoreceptor 24, thereby exposing blue light.

As shown in FIG. 6, the lamp carriage 15
When the carriage 15 strokes _L0 , the carriage 15 returns at a faster speed than the forward stroke, travels a stroke _L1 , and stops in the state shown in FIG. 7. At this point, light source 2 (main wavelength is green) is turned on,
It travels a stroke L ₀ and performs scanning exposure during that travel. The traveling path of the reflected light in this case is as described above, so the explanation will be omitted, but the movement of the lamp carriage 15 and the photosensitive drum 24 are synchronized, and the previously exposed blue image and the current one are It is made to match the green exposure image.

When the scanning exposure by the light source 2 is completed, the lamp carriage 15 starts the stroke as in the case of the light source 1.
Return L ₁ to stop. At the same time as the light source 3 is stopped, the light source 3 is turned on, and the lamp carriage 15 again runs the stroke L ₀ to scan the original 1, forming a red exposure image on the photoreceptor drum 24, and each of the light sources 1, 2, and 3 Three-color exposure is performed by scanning,
Color printing can be done.

This completes one copying cycle, but in the second copying cycle, contrary to the above, the light source 3 is turned on, the lamp carriage 15 is scanned and exposed by the stroke _L0 , and then the stroke _L2 is returned, and the light source 2 stops at the home position 25. Immediately after stopping, only the light source 2 is turned on to scan and expose the stroke L ₀ , and then the stroke L ₂ is returned and the light source 1 stops at the home position 25 . Here light source 1
Only the lamp is lit and the lamp carriage 15 travels to perform scanning exposure. As described above, exposure is performed in the order of red, green, and blue, and the second cycle of copying is completed.

In addition, in the above, strokes L ₁ and L ₂ are
For the stroke L ₀ which is the scanning distance, L ₁ <L ₀ <
L ₂ is equal to the scanning distance L ₀ plus the distance d between light sources 1 and ₂ (or the distance between light sources 2 and 3). That is, in odd-numbered copying cycles, scanning exposure is performed in the order of B (Blue) → G (Green) → R (Red), and in the even-numbered copying cycles, scanning exposure is performed in the order of R → G → B. As a result, the return stroke length of the lamp carriage 15 can be suppressed to a minimum length, the return time of the carriage can be shortened, and the copying speed can be increased. In the above embodiments, the original is fixed and the scanning system is moved, but the scanning system may be fixed and the original is moved.

〔Effect of the invention〕

As explained above, according to the scanning exposure device for a color copying machine of the present invention, a plurality of light sources with different spectral characteristics are arranged below the platen, and these light sources are turned on in the order of arrangement to perform scanning exposure. When the number of cycles exceeds 2, the light sources are turned on alternately in the arrangement order and in the reverse order, reducing power consumption by using a low power consumption light source (approximately 1/3 compared to conventional halogen lamps). ), and the copying speed can be increased.

[Brief explanation of drawings]

1 and 2 are configuration diagrams of a scanning exposure device of a conventional color copying machine, FIGS. 3A and 3B are wavelength characteristic diagrams showing the spectral characteristics of a light source, and FIG. 4 is a configuration of an embodiment of the present invention. 5 is a wavelength characteristic diagram showing the spectral characteristics of the light source according to the present invention, FIG. 6 is an explanatory diagram showing the moving state of the lamp carriage shown in FIG. 4, and FIG. 7 is an explanatory diagram showing the operating state of each part. Time chart shown. Explanation of symbols 1... Original, 2... Platen, 1
1, 12, 13...Light source, 14...Rail, 15
... Lamp carriage, 16 ... Scanning system drive wire, 17, 19, 21, 23 ... Mirror, 18,
20...Mirror carriage, 22...Lens, 2
4...Photoreceptor.

Claims (1)

[Claims] 1. A platen on which a document is placed is irradiated with light, and the reflected light is imaged on a photoreceptor for each spectral region to form a latent image, which is then subjected to development, transfer, and fixing steps. In a copying machine that performs copying, a plurality of light sources having different spectral characteristics are installed at predetermined intervals, and a relative displacement is applied between a document on a platen and the plurality of light sources to adjust the displacement. a scanning drive mechanism that sequentially scans and exposes the document for each of the plurality of light sources based on the arrangement order of the plurality of light sources; A scanning exposure device for a color copying machine, comprising: a control means for causing the scanning drive mechanism to perform scanning exposure.