JPH0466496B2 - - Google Patents

Description

Detailed Description of the Invention A. Object of the Invention [Field of Industrial Application] The present invention relates to a microfilm reader printer. More specifically, the present invention relates to a reader printer using an automatic print image density adjustment method.

[Prior Art] The density of frame images of original film photographed and recorded on microfilm varies among individual frame images. Therefore, the reader printer is equipped with a manual image density adjustment means such as a knob or dial so that the density of the output print image can be adjusted as desired depending on the density of the film image to be printed (enlarged copy). I've let it happen.
That is, by moving a knob or the like, the image forming execution condition values of the printing mechanism, such as the image exposure amount to the photoreceptor and the developing bias value, are changed according to the amount of movement, and a print with a desired image density is output.

Recently, in order to save the trouble of manually adjusting print image density as described above, the density of the target frame image to be printed is automatically measured, and the image forming execution condition value of the printing mechanism is automatically changed to an appropriate value according to the photometered value. An automatic print image density adjustment system has been introduced.

[Problems to be Solved by the Invention] Among the print image density automatic adjustment systems, there is one in which the density of a frame image is photometered in the optical path of the reader system before starting image scanning for printing.

However, the conventional photometry method has the disadvantage that when the photometry sensor is placed on the screen of the reader system, it casts a shadow and the image is missing. This results in disadvantages such as increased cost and poor photometric accuracy since only the amount of reflected light can be measured.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reader printer using an automatic image density adjustment method that does not have the above-mentioned problems.

B. Structure of the Invention [Means for Solving the Problems] The present invention automatically measures the density of a film image to be printed, and automatically changes the image forming execution condition values of the printing mechanism in accordance with the measured value. In a reader printer with an automatic print image density adjustment system, when in reader mode, it is held at a predetermined first angular posture position and forms the reader system optical path from the film illumination section to the projection screen, and when switched to print mode, the support shaft is rotated at a predetermined speed to a predetermined second angular posture position, forming a printing system optical path from the film illumination section to the image exposure section of the printing mechanism, and the movement of the reflected light due to the rotation causes the above-mentioned The image exposure section is equipped with a rotating mirror for slit exposure of a film image, and a density photometry sensor disposed outside the reader system optical path and the print system optical path, and the mirror is rotated by switching to print mode. The object of the present invention is to provide a reader printer characterized in that it is configured such that moving reflected light from the rotary mirror is sequentially received by a photometric sensor to perform image density photometry for automatic print image density adjustment.

[Function] With the above configuration, photometry of film image density for automatic print image density adjustment is performed by switching the device to print mode and starting the rotation of the rotating mirror. This is performed by a sensor placed inside the reader system optical path and outside the printing system optical path. Therefore, the sensor can be efficiently installed in a space outside the optical path of the reader system and print system, and the density can be photometered in a short time by rotating the mirror.

In addition, the above-mentioned problems do not occur, the mechanism is excellent in accuracy, and the mechanism for moving the mirror in and out of the optical path,
This type of reader printer can be obtained at low cost with a simple configuration and no half mirror or the like.

[Embodiment] The drawing shows a schematic configuration of an example of a reader printer according to the present invention.

In Fig. 1, 1 is a film illumination section consisting of a lamp L, a condensing lens, a heat insulating filter, etc., F is a micro film, and the desired frame image section Fa is manually or automatically located at the search position of the film illumination section. be done. Reference numeral 2 designates a projection lens, 3 a rotating mirror driven to rotate around a support shaft 3a, 4 a fixed first mirror, 5 a fixed second mirror, and 6 a projection screen.

In the reader mode, the rotating mirror 3 is the first one indicated by the solid line.
This forms a reader system optical path from the film illumination section 1 to the projection lens 2 to the mirror 3 to the mirror 4 to the mirror 5 to the projection screen 6. The target film frame image Fa is enlarged and projected onto the screen 6.

7 is a fixed third mirror, 8 is a fixed fourth mirror, 9
is the printing mechanism. The printing mechanism 9 in this example is a transfer type electrophotographic copying mechanism. Reference numeral 10 denotes a photosensitive drum that is rotated in the direction of the arrow, and around this photosensitive drum are necessary image forming process equipment such as a charger 11, a slit plate 12, a developer 13, a transfer charger 14, and a cleaning device 15. It is arranged. 1
6 is a paper feed cassette, 17 is a fixing device, and 18 is a paper discharge tray.

20, as shown in the second figure, a plurality of photometric sensors (which may be one long one-dimensional sensor array) arranged near the upper side of the fixed first mirror 4 at intervals along the upper side; 21 is an arithmetic control circuit, 22
shows a film lighting lamp dimmer circuit.

When the reader mode is switched to the print mode by a switching means (not shown), the control system of the print mechanism 9 is turned on, and the photosensitive drum 10 is driven to rotate at a predetermined speed. Then, the rotating mirror 3 held at the first angular posture position shown by the solid line is moved to the support shaft 3a.
The photosensitive drum 10 is rotated by a drive mechanism (not shown) at a predetermined constant speed synchronized with the rotational circumferential speed of the photosensitive drum 10 to a second angular posture position shown by a two-dot chain line.

As the mirror 3 rotates, the reflected light of the film frame image light incident on the mirror 3 from the projection lens 2 side is sequentially directed from the direction toward the fixed first mirror 4 to the direction toward the fixed third mirror 7. I will move to. The light incident on the mirror 7 is reflected by the mirror and sequentially enters the surface of the rotating photosensitive drum 10 along a path from the fixed fourth mirror 8 to the slit plate 12. That is, by rotation of the mirror 3, an enlarged image of the film frame image Fa is slit-exposed on the surface of the rotating photosensitive drum 10, and an enlarged toner image corresponding to the film frame image Fa is formed on the circumferential surface of the rotating photosensitive drum 10 according to the known image forming principle. are sequentially formed, and the toner images are sequentially transferred to the surface of the transfer material P that is synchronized with the rotation of the drum 10 and fed to the transfer section 14, and the transfer material P is transferred to the tray 18 via the fixing device 17. be discharged. That is, an enlarged copy Pa of the target film frame image Fa is printed out.

On the other hand, as the mirror 3 rotates, each photometric sensor 20 is scanned by the moving reflected light in the process of sequentially moving from the fixed first mirror 4 side toward the fixed third mirror 7, and the amount of light is Photometry is performed.
This photometry is performed continuously until the reflected light corresponding to the leading edge of the image enters the photometric sensor 20 and the reflected light corresponding to the trailing edge of the image finishes passing through the photometric sensor.

The circuit 21 calculates the average light amount from the light amount detected by each sensor 20, and calculates the appropriate film illumination light amount corresponding to that light amount, that is, the appropriate exposure light amount for the photosensitive drum 10. The illumination lamp dimming circuit 22 is controlled. That is, the image density of the film frame image Fa is automatically photometered, the image forming execution conditions are automatically controlled in real time according to the image density, and the print Pa is output with the image density automatically adjusted to an appropriate value.

When the rotating mirror 3 reaches the second angular attitude position, it is rotated back to the first angular attitude position.

In the case of multi-copying, the rotation operation of the rotary mirror 3 from the first angular posture position to the second angular posture position and the copying operation of the print mechanism are repeated a required number of times.

Based on the film frame image density measurement value by the photometric sensor 20, the developing bias value and other detections during image formation may be controlled to output a print with an appropriate image density.

The mirror 3 may be rotated 90° or 180° about the optical axis or moved out of the optical path to switch from the reader mode to the print mode, and photometry may be performed at that time.

C. Effects of the Invention As described above, according to the present invention, the apparatus is switched to the print mode, the rotation of the rotating mirror is started, and during the rotation of the mirror, the position outside the reader system optical path and the printing system optical path is This is done by a sensor placed on the Therefore, the sensor can be efficiently installed in a space outside the optical path of the reader system and print system, and the density can be photometered in a short time by rotating the mirror.

In addition, the above-mentioned problems do not occur, and the mechanism is excellent in accuracy, and the mechanism for moving the mirror in and out of the optical path,
This type of reader printer can be obtained at low cost with a simple configuration and no half mirror or the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an example of a reader printer according to the present invention, and FIG. 2 is a perspective view of a fixed first mirror and a photometric sensor portion. 3 is a rotating mirror, and 20 is a photometric sensor.

Claims (1)

[Scope of Claims] 1. A reader printer with an automatic print image density adjustment method that automatically measures the density of a film image to be printed and automatically changes image formation execution condition values of a printing mechanism appropriately according to the photometered value, In the reader mode, it is held at a predetermined first angular posture position to form a reader system optical path from the film illumination section to the projection screen, and when switched to print mode, it is held at a predetermined second angular posture position around the support shaft. is rotated at a predetermined speed to form a printing system optical path from the film illumination section to the image exposure section of the printing mechanism, and the film image is slit-exposed to the image exposure section by the movement of reflected light due to the rotation. a movable mirror, and a density photometry sensor disposed outside the reader system optical path and the print system optical path, and the moving reflected light from the rotatable mirror is provided during a rotation operation of the mirror due to switching to a print mode. A reader printer characterized in that the reader printer is configured to sequentially receive light onto a photometric sensor and perform image density photometry for automatic print image density adjustment.