Background of the Invention
1. Field of the Invention
The present invention relates to a printer with a paper supplying device for supplying a paper by manual insertion from manual insertion part and by automatic insertion from sheet storage part.
2. Description of Related Art
Conventionally, in a printer including a paper supplying device having both of a manual insertion mechanism and an automatic insertion mechanism, when printing paper, for example an overhead projector (OHP) sheet, was manually inserted for a continuous printing, it was necessary to insert a subsequent sheet after the previously inserted sheet had been completely transported from a printing part to a point where the preceding and subsequent sheets do not overlap. Therefore, the operator determined a time for inserting the subsequent sheet and inserted it into the printer.
However, the time for inserting the subsequent sheet varied with the operator. That is, when the operator inserted the subsequent sheet too rapidly, the subsequent sheet was fed simultaneously with the initial sheet. When the operator was slow inserting the subsequent sheet, a sheet normally of a different type, stored in the sheet cassette, was automatically supplied. Both cases were inconvenient for the operator and increased copying time.
Summary of the Invention
An object of the present invention is to provide a printer with a paper supplying device with which the operator can manually insert a paper without the operator having to time that insertion when multiple pages are to be printed.
In order to achieve this object, the printer with a paper supplying device of the present invention comprises a first detection means for detecting whether or not the paper supplied by manual insertion is in the paper feeding path, a second detection means for detecting whether or not the paper supplied by automatic insertion is in the paper feeding path, and informing means for informing the operator that the subsequent paper can be inserted when no paper is detected in the feeding path by the first and second detection means.
The informing means of the present invention informs the operator that the subsequent paper can be inserted when the first detection means judges the paper supplied by manual insertion is not in the paper feeding path and the second detection means judges that the paper supplied by automatic insertion is not in the paper feeding path.
According to the printer with a paper supplying device of the present invention including first detection means for detecting whether or not the paper supplied by a manual insertion is in a paper feeding path, second detection means for detecting whether or not the paper supplied by an automatic insertion is in the paper feeding path, and informing means for informing that the following manual insertion paper can be inserted when no paper is detected in the feeding path by the first and second detection means, the operator does not miss the timing of the manual insertion of the paper.
Brief Description of the Drawings
A preferred embodiment of the present invention will be described in detail with reference to the following figures wherein:
FIG. 1 is a schematic illustration of a laser printer which embodies the present invention;
FIG. 2 is a block diagram of the controller;
FIG. 3A is a flowchart showing the print processing control of the present invention; and
FIG. 3B is a table of labels for the flowchart of FIG. 3A.
Detailed Description of the Preferred Embodiment
Referring now to the accompanying drawings, a preferred embodiment of the present invention will be described in detail.
FIG. 1 is a schematic illustration of a laser printer which is one embodiment of the present invention. A paper cassette 3, which stores a printing paper 2 for automatic insertion, is detachably mounted at a lower position in the laser printer main body 1. The printing paper 2 in the paper cassette 3 is fed into the laser printer main body by an automatic insertion roller 4 installed above the paper cassette 3. As the printing paper 2 is fed into the laser printer main body 1, it passes through paper feeding paths 8a and 8b to a photo-sensitive drum 10 on which transcript material is formed by a series of printer processes. An automatic insertion paper detecting sensor 6, for detecting whether a printing paper 2 has been automatically inserted into the paper feeding path 8a, is installed in the paper feeding path 8a. At the photosensitive drum 10, the transcript material is transcribed from the photosensitive drum 10 to the printing paper 2 and the image formed thereon. Then, the printing paper 2, on which the transcript material is transcribed, passes between a pair of fixing rollers 12, and the transcript material is fixed on the printing paper 2 thereby. The printing paper 2, on which the transcript material is fixed, is then discharged from a discharging tray 14 mounted on one side of the laser printer main body 1.
A manual insertion tray 16 is provided for the manual insertion of a printing paper 15 and is positioned above the paper cassette 3. A manual insertion sensor 18 for detecting whether a printing paper 15 is on the manual insertion tray 16 is installed on the side of the laser printer main body 1 where the manual insertion tray 16 and feed path enter the laser printer main body 1. Printing paper 15 put on the manual insertion tray 16 is moved into the laser printer main body 1 by a manual insertion roller 20 arranged in the laser printer main body 1 over the manual insertion tray 16, where it enters the laser printer main body 1, based on the signal from the manual insertion sensor 18. The printing paper 15 moved into the laser printer main body 1 passes along paper feeding path 8c, which joins the paper feeding path 8b, to be delivered to the photosensitive drum 10. Moreover, a manual insertion paper detecting sensor 22 for detecting whether a printing paper 15 is in the paper feeding path 8c is installed in the paper feeding path 8c. The paper sensors 6, 18 and 22 are conventional optical reflecting type sensors having a light emitting part and light receiving part similar to ones disclosed in U.S. Pat. No. 4,778,296 and U.S. patent application Ser. No. 07/185,761, filed Apr. 25, 1988 which corresponds to published European Patent Application No. 288,089. Further, a LED 24, that indicates when the user can put the subsequent printing paper 15 on the manual insertion tray 16, is installed on an upper side of the laser printer main body 1.
The controller for the laser printer will be described with reference to FIG. 2.
The controller is a microcomputer 58 which consists of a CPU 50, a ROM 52, a RAM 54 and a bus 56. The ROM 52 includes a program area 52A for storing programs for printing operations. The CPU 50 executes each operation according to the programs stored in program area 52A. The RAM 54 works as a working memory when the CPU 50 executes each operation. When print data is input to the microcomputer 58 from a host computer 60, the printing operations are executed.
The LED 24, a manual insertion solenoid 70, an automatic insertion solenoid 72, and a main motor 74 connect to the microcomputer 58 through a LED control circuit 62, a manual insertion solenoid control circuit 64, an automatic insertion solenoid control circuit 66, and a main motor control circuit 68 respectively. Further, the manual insertion sensor 18, the manual insertion paper detecting sensor 22, and the automatic insertion sheet sensor 6 connect to the microcomputer 58.
The main motor 74 drives the photosensitive drum 10, the fixing rollers 12, the automatic insertion roller 4, and the manual insertion roller 20 through a transmission member. The transmission member, between the main motor and the automatic insertion roller 4 and the manual insertion roller 20, includes clutch members which transfer the rotation power to the automatic insertion roller 4 or the manual insertion roller 20 when the corresponding insertion solenoids 70, 72 are driven. Therefore, the automatic insertion roller 4 is rotated by the main motor 74 only when the automatic insertion solenoid 72 is driven and the manual insertion roller 20 is rotated by the main motor 74 only when the manual insertion solenoid 70 is driven.
The printing operation in this laser printer will now be explained using the flowchart of FIGS. 3A and 3B.
When print data is input by the host computer 60, the laser printer starts the printing operation. First, the main motor 74 is driven and the photosensitive drum 10 starts to rotate and is kept rotating to obtain a fixed rotation speed. After the rotation speed of the photosensitive drum 10 becomes the fixed, the LED 24 is turned off indicating to the operator that manual insertion of a printing paper is prohibited at that time (S2). Next, the manual insertion sensor 18 judges whether a printing paper 15 is in the manual insertion tray 16 (S3). When it is judged that a printing paper 15 is in the manual insertion tray 16 (S3.YES), the manual insertion solenoid 70 is driven to rotate the manual insertion roller 20 and the manual insertion paper 15 is supplied into the laser printer main body 1 (S4). When it is judged that the printing paper 15 is not in the manual insertion tray 16 (S3.NO), the automatic insertion solenoid 72 is driven to rotate the automatic insertion roller 4 and a printing paper 2 stored in the sheet cassette 3 is supplied in the laser printer main body 1 (S5). Either the manual insertion paper detecting sensor 22 or the automatic insertion paper detecting sensor 6 confirms that a printing paper is supplied to the paper feeding path (S6).
When the predetermined time, that is, the time for the printing paper to reach the photosensitive drum 10, passes, the image forming operation is started (S7). In the image forming operation the photosensitive drum 10 is exposed to a laser beam to form an electrostatic latent image on the photosensitive drum 10 to which toner adheres. The toner image, corresponding to the latent image, is transferred from the photosensitive drum 10 onto the printing paper. This image forming operation is conventional and is the same as the one disclosed in the U.S. Pat. Nos. 4,708,455 and 4,470,689.
Once the image forming operation is started, the manual insertion paper detecting sensor 22 and the automatic insertion paper detecting sensor 6 continue to indicate the presence of the printing paper in the paper feeding path until the printing paper clears the applicable sensor (S8). When the applicable sensor no longer detects a printing paper in the paper feeding path (S8.NO), the manual insertion solenoid 70 or the automatic insertion solenoid 72 is stopped to stop rotating the manual insertion roller 20 or automatic insertion roller 4 (S9). Simultaneously, as both sensors now indicate no paper is present, the LED 24 is turned on which indicates to the operator that it is possible to insert a printing paper 15 in the manual insertion tray 16 (S10). After the present printing processing is terminated (S11), it is judged whether or not the subsequent printing paper is continuously printed (S12). When it is judged that the subsequent printing paper is printed (S12.YES), the flow returns to the S2, the LED 24 is turned off and the subsequent printing paper is supplied.
When it is judged that no printing remains to be done (S12.NO), the main motor 74 is stopped (S13) and the printing operations are terminated.
As mentioned above, the operator has only to insert the printing paper 15 for manual insertion in the manual insertion tray 16 while the LED 24 is turned on, that is, during the time between the feeding of the last printing paper to the paper feeding path and the end of the present print processing. Therefore, the operator should not manually insert the printing paper at an inappropriate time.
Although the present invention has been shown and described in terms of the preferred embodiment thereof, with reference to the drawings, it should not be considered to be limited thereby, since the details of any particular embodiment could be varied without departing from the scope of the invention. For example, the automatic insertion paper detecting sensor 6 and the manual insertion paper detecting sensor 22 may be one and the same and a buzzer or a LCD can be used for the informing means instead of or in addition to the LED 24.