JP2802192B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, and more particularly, to an image forming apparatus such as a copying machine having a zooming function such as enlargement and reduction.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine having a zooming function generally has a zooming optical system, and the zooming optical system is controlled according to a magnification specified by a panel key input or the like. By moving a constituent lens, a photosensitive drum or the like is exposed to light for image formation through the lens to form an image subjected to a magnification change process. When the magnification is changed only once, the operation of moving the lens when changing the magnification can be performed relatively easily by the operation of a lens driving motor or the like. However, if the magnification is specified again during the movement of the lens, the operation of moving the lens becomes relatively complicated.

[0003] Conventionally, with respect to magnification specified key and the lens operation control of this kind of scaling function with a copying machine, Tokuoyake flat 2-522
No. 64, Japanese Patent Publication No. 3-56460, and the like.

In Japanese Patent Publication No. 2-52264, when a magnification change instruction is issued many times during the movement of the lens to the first designated magnification position, the lens drive mechanism is designed to wait a short time before moving the lens. By controlling, waste of the lens operation is eliminated.

On the other hand, in Japanese Patent Publication No. 3-56460,
When a magnification change instruction is issued many times during the movement of the lens to the designated magnification position, the operation time is reduced by controlling the lens driving mechanism so as to immediately change the movement target of the lens.

[0006]

Generally, in an image forming apparatus such as a copying machine, there is a strong demand for faster processing and higher image quality of a processed image.

However, the above-mentioned conventional Japanese Patent Publication No. 2-52
In No. 264, when a magnification change instruction is issued many times during movement of the lens to the first designated magnification position, it takes time to reach the final designated magnification, although there is no waste in lens operation. On the other hand, in Japanese Patent Publication No. 3-56460, when a magnification change instruction is issued many times while the lens is moving to the first designated magnification position,
Although the operation time can be reduced in some cases, since the moving operation is performed one by one until the lens reaches the final designated magnification, the lens often results in useless movement.

Further, in any of these methods, the actual operation of the lens uses a gear or the like, but there is a concern about a problem of focusing accuracy at the time of reverse rotation due to a difference in gear backlash at the time of forward / reverse rotation. In other words, there is a problem that the focusing accuracy is reduced depending on the final moving direction reaching the designated magnification position.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide an image forming apparatus which has good operability and can improve focusing accuracy when changing magnification.

[0010]

[0011]

For the image forming apparatus of the present Application SUMMARY other to achieve the above to solve the problems described above, the image formation to form a variable magnification images using the light for image formation through variable power optical system A lens disposed in the optical path of light in the variable power optical system and configured to be movable in the optical axis direction, instruction means for instructing a desired magnification, and instruction by the instruction means. Driving means for moving the lens to a position corresponding to the magnification,
When the second magnification is instructed by the instruction means while the lens is being moved in the first direction in accordance with the first magnification instructed by the instruction means, the lens should be moved in accordance with the second magnification. It is determined whether the second direction is the same as the first direction. If the two directions are the same, the lens is moved to a position corresponding to the second magnification. If not, the movement of the lens is interrupted. And a control means for controlling the driving means to move the lens once to a reference position and to move the lens to a position corresponding to the second magnification with reference to the reference position.

[0012]

[0013]

According to the image forming apparatus of the effects of the present patent application, first, when an instruction of the first magnification by instructing means, drive means, an attempt to move the lens to a position corresponding to the first magnification. Here, while the driving means is moving the lens in the first direction,
When the second magnification is further instructed by the instruction means, the control means determines whether or not the second direction to be moved and the first direction are the same according to the second magnification. If they are the same, the driving means moves the lens to a position corresponding to the second magnification as it is under the control of the control means. Here, if the direction is the same, when reversing the moving direction,
For example, since there is no error in the moving distance due to gear backlash or the like, it is possible to relatively accurately move to the position corresponding to the second magnification even if it is moved as it is, and furthermore, the time until the movement is completed. Can be relatively short. On the other hand, if not identical, the driving means:
Under the control of the control means, the movement of the lens is interrupted and the lens is temporarily moved to a reference position. After the lens is moved to this reference position, the lens is moved to a position corresponding to the second magnification based on the reference position. Move the lens. As a result, useless movement of the lens can be further reduced, and the lens can be more quickly and accurately moved to a position corresponding to the second magnification.

The following examples of the present invention will further clarify such an operation of the present invention, and will further clarify other operations of the present invention.

[0015]

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

FIG. 1 is a schematic block diagram of a control system of a copying machine according to an embodiment of the present invention.

In FIG. 1, the control system includes a microcomputer 1, an operation panel 2, a motor drive circuit 3, and a lens drive motor 4. The microcomputer 1 constitutes an example of the control means, and controls the overall operation of the copying machine in accordance with a predetermined program. In particular, the microcomputer 1 performs a lens movement control associated with a magnification change operation as described later. Have been. The operation panel 2 constitutes an example of an instructing means, and includes various keys as described later. By operating the keys, the operator can perform normal copy processing, A color copying process, a scaling copying process, and the like can be performed. The motor drive circuit 3 and the lens drive motor 4 constitute an example of a drive unit, and are used to move the lens to a position corresponding to the designated magnification at the time of variable-magnification copying. .

The control system further includes an LHPS (Lens Home Position Center) 5, which is a reference position detection sensor for setting the focus of the lens. LHPS5 is
One end is connected to +5 V (volt), and when the lens unit reaches a home position, which is an example of a reference position, as will be described later, the microcomputer 1 operates by opening and closing a switch.
It is configured to inform that fact.

FIG. 2 shows an example of the operation panel 2.

In FIG. 2, an operation panel 2 is an enlarged key.
21, a reduction key 22 and a magnification display unit 23 are provided. When the enlargement key 21 or the reduction key 22 is pressed, a desired fixed magnification can be set and instructed. The instruction magnification is displayed on the magnification display unit 23. The operation panel 2 further includes a numeric keypad 24 for instructing the number of copies and the like, and a copy for instructing execution of the copy.
It includes a key 25, a copy number display section 26 for displaying the set copy number and the copied number, a magnification automatic selection display lamp 27, and various control keys and display lamps.

FIG. 3 shows a schematic configuration of a copying machine provided with the control system of FIG.

In FIG. 3, the copying machine is provided with a copy lamp 31 for illuminating the original, a plurality of mirrors 32 for guiding the reflected light from the original to the exposure optical system, and an optical path for the reflected light. The lens unit 33 is configured to move left and right in accordance with the set magnification, the lens drive motor 4 also shown in FIG. 1 for moving the lens unit 33, and exposure is performed by the guided reflected light. Photoconductor drum 35,
A main charger 36 for forming an electrostatic latent image on the photosensitive drum 35; a developing device 38 for color or black and white development of the electrostatic latent image using the toner; a toner storing the toner;
A box 39, a cleaner unit 40 for cleaning the photosensitive drum 35, a transfer charger 41 for transferring a toner image to a sheet, and a transport device 42 for transporting the sheet on which the toner image has been formed. And a fixing device 43 for fixing the toner image of the conveyed sheet by a thermal action.

According to such a configuration, when the magnification is changed by a key operation on the operation panel 2 in FIG. 1, the lens unit 33 is controlled by the microcomputer 1 in FIG. By means of the data 4, it is moved to a position corresponding to the designated magnification, and a variable magnification copying operation with a desired magnification can be performed.

FIG. 4 shows a lens unit moving mechanism and a variable power optical system in the copying machine shown in FIG.

In FIG. 4, the driving mechanism includes a lens driving motor 4, a lens driving wire 51 for transmitting the driving force of the lens driving motor 4 to the lens unit 33, and a lens slide base shaft 52. The moving position control is performed based on the LHPS 5 using the lens driving motor 4 as a stepping motor.

Incidentally, as shown in FIG.
3 has a lens 33a. The lens 33 a is arranged in the optical path of light for image formation guided from the document by the plurality of mirrors 32, and together with the lens unit 33,
It is movable in the direction of the optical axis. In addition, a plurality of Mira-3
2 is a mirror drive motor 55 and a mirror drive wire 56
The mirror base position sensor (MBHPS) 57 can be moved to a desired position in accordance with the magnification by using the mirror base position sensor (MBHPS) 57 by using a, 56b and the like. Furthermore,
The copying machine includes a color copying CCD unit 61, an AE sensor 62, a temperature fuse 63, a document detection light receiving substrate 64, and the like.

The operation of the lens driving mechanism configured as described above will be described below with reference to FIGS.

First, when the first magnification is designated by pressing the enlargement key-21 or the reduction key 22 on the operation panel 2, the magnification is displayed on the magnification display section 23 of the operation panel 2. At the same time, the lens drive motor 4 is driven to move the lens unit 33 to the designated magnification. When the second magnification designation input is performed from the operation panel 2 during the lens moving operation, the display on the magnification display section 23 is first changed to the second designated magnification and displayed. Then, the microcomputer 1 determines the moving direction from the first designated magnification and the second designated magnification, and in the case of the same direction, changes the moving target to a position corresponding to the second designated magnification and performs the moving operation. On the other hand, when the moving direction is reversed, the lens unit 33 is temporarily stopped in order to suspend the moving operation and increase the focusing accuracy such as gear backlash.
To its home position. After the movement to the home position is completed, the magnification display unit 23 at that time is displayed.
Start and end the movement to the latest designated magnification displayed in.

Hereinafter, the movement control of the lens unit 33 by the microcomputer 1 will be described with reference to the flowchart of FIG.

In FIG. 5, the microcomputer 1 monitors whether or not there is a first magnification change instruction from the operation panel 2 (Step S).
1) If present (YES), proceed to step S2,
A magnification change display is performed on the magnification display section 23. Subsequently, the lens drive circuit 4 is operated by the lens drive circuit 3 to move the lens unit 33 to a position corresponding to the designated magnification (step S3). During such movement, the microcomputer 1
Monitors whether there is a second zooming instruction from the operation panel 2 (step S4), and if there is (YES), branches to step S5 and performs a magnification change display on the magnification display unit 23. .

Here, by comparing the first magnification and the second magnification, it is determined whether or not the moving direction of the lens unit 33 is the same direction (step S6). If the directions are the same (YES), the flow branches to step S7, and the lens unit 33 is moved by changing the target position while continuing the movement operation. Then, the movement operation is continued until the movement is completed (step S8), and when the movement is completed (YES), the process proceeds to step S21, in which the lens driving motor 4 is stopped and a series of operations is ended.

On the other hand, in step S6, if the moving direction of the lens unit 33 is the opposite direction (NO), the flow branches to step S9. In step S9, the movement of the lens unit 33 is temporarily stopped, and the lens home position (LH
The lens drive motor 4 is driven to move to P).
Then, the moving operation is continued until the lens home position is detected by the LHPS 5 (step S10). When the lens home position is detected (YES), the process proceeds to step S11, where the lens unit 33 is moved to the second position based on the lens home position. The lens drive motor 4 is operated to move to the zoom position. Then, the movement operation is continued until the movement is completed (step S12). When the movement is completed (YES), the process proceeds to step S21, and the lens driving motor 4 is stopped.

On the other hand, if there is no second zooming instruction in step S4 (NO), the flow branches to step S20, and steps S3 and S4 are repeated until the movement is completed. The movement operation is continued while confirming, and when the movement is completed (YES), the process proceeds to step S21, and the lens driving motor 4 is stopped.

As described above, according to the present embodiment, if the second zooming instruction is issued during the movement of the lens unit, it is determined whether the movement direction of the lens unit is the same direction or the opposite direction. If the difference in gear backlash of the drive mechanism adversely affects the focus of the lens, the lens unit is moved to the target position after moving to the lens home position. Therefore, the adverse effect of the gear backlash can be eliminated. As a result, accurate focusing can be performed by using the lens unit after the movement, which is extremely advantageous.

In the embodiment, one lens home position is used. However, the number of lens home positions is not limited to one and may be two or more.

In the present embodiment, when the second magnification change instruction is issued during the movement of the lens unit, it is first determined whether the movement direction of the lens unit is the same direction or the opposite direction. In order to simplify the apparatus and control, such a determination is omitted, and if there is a second zooming instruction during the movement of the lens unit, the lens unit is moved to the lens home position. Positioning, and thus accurate focusing, is possible.

[0037]

[0038]

According to the image forming apparatus of the present gun, as described above in detail, according to the present invention, a drive means for moving the lens corresponding to the magnification instructed by the instruction unit position, the instructed by the instruction means 1 When the second magnification is instructed by the instruction means while the lens is being moved in the first direction according to the second magnification, the second direction to be moved according to the second magnification and the first It is determined whether or not the directions are the same. If the directions are the same, the lens is moved to the position corresponding to the second magnification as it is. If the directions are not the same, the movement of the lens is interrupted and the lens is temporarily moved to the reference position. And control means for controlling the driving means to move the lens to a position corresponding to the second magnification with reference to the reference position, so that useless movement of the lens can be further reduced, and more quickly Relatively accurate It is possible to move the lens to a position corresponding to a second magnification. Further, unlike the conventional example, adverse effects due to the difference in gear backlash are extremely low.

As a result, according to the present invention, when changing the magnification, it is possible to realize an image forming apparatus which has good operability and can improve the focusing accuracy, and which can meet the demands for faster processing and higher quality of processed images.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a control system of a copying machine according to an embodiment of the present invention.

FIG. 2 is a plan view of an operation panel of the copying machine according to one embodiment of the present invention.

FIG. 3 is a schematic sectional view of a copying machine according to an embodiment of the present invention.

FIG. 4 is a plan view of a lens unit moving mechanism of the copying machine shown in FIG. 3;

FIG. 5 is a flowchart showing a magnification operation of the copying machine of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microcomputer 2 Operation panel 3 Motor drive circuit 4 Lens drive motor 5 LHPS 21 Magnification key 22 Reduction key 23 Magnification display unit 31 Copy lamp 33 Lens unit 33a Lens 51 Lens drive wire 52 Lens slide base shaft

Claims (1)

(57) [Claims] 1. An image forming apparatus which forms an image to be variable in magnification using light for image formation via a variable magnification optical system,
A lens arranged in the optical path of the light in the variable power optical system and configured to be movable in the optical axis direction, an instruction unit for instructing a desired magnification, and a magnification instructed by the instruction unit. A driving unit for moving the lens to a corresponding position, and a second magnification by the indicating unit while the lens is being moved in a first direction in accordance with the first magnification indicated by the indicating unit. Is designated , the second double
The second direction to be moved according to the rate and the first direction
Judge whether they are the same, and if they are the same,
The lens should be moved to a position corresponding to the second magnification.
If they are not the same, the movement of the lens is interrupted and the lens is temporarily moved to a reference position, and the driving means is controlled to move the lens to a position corresponding to the second magnification based on the reference position. An image forming apparatus comprising: