Technical Field

The present invention relates to a printing apparatus which has only one print station, but which is capable of printing on two different types of record media, one being a continuous type of record medium, such as a receipt, which is stored in the printer, and the other being another type of record medium, such as a slip, which is introduced to the printer from outside.

Background Art

An example of a one-station two-function printer is disclosed in Japanese Patent Application No. 42474/81 in which a -receipt feed guide is moved between two positions in two printing modes to allow printing on a receipt or to withdraw said receipt from the print station thereby to permit insertion of and printing on another record medium.

Also, Japanese Patent Application No. 14978/84 discloses a printer of the type in which a paper not to be printed is withdrawn until it reaches a passage outside of a print station to permit the insertion and transport of a paper to be printed on and in which feed rollers respectively adapted to feed two types of paper can be selectively driven by one motor.

Disclosure of the Invention

In the above-mentioned conventional printers, switching means to change the passage for a record medium itself or to switch rollers to be connected with a carrier motor is needed in order to perform printing on two different record media at one station and hence the structures thereof are relatively complicated.

In addition, since a slip is frequently thicker than a receipt, it is desirable to adjust a gap between the print head and the platen in proportion to the thickness of the slip. Accordingly, the prior art needs a mechanism for the gap adjustment in addition to the above mentioned means. As has been described above, in the conventional one-station two- function printer, various switching means are needed in order to switch various elements of the printer in conformity with various record media, so that the general structure of such a printer is relatively complicated.

An object of the present invention is to provide a printer in which printing on two record media of different thicknesses is performed at a single printing station in a simple manner.

Thus, according to the invention, there is provided a printing apparatus for printing on a first kind of record medium which is in a continuous form and is provided from a supply contained within the printing apparatus, and also for printing on a second kind of record medium which is introduced into the printing apparatus from its exterior, including a printhead and platen defining a printing station, and transport means for moving the two kinds of record medium, characterized by a platen arm carrying the platen and pivotally mounted for movement between a first position in which said platen is remote from said printhead, and a second position in which said platen is adjacent to said printhead, said transport means including first and second roller means so arranged that, when said platen arm is in said first position, said first roller means is operable either to withdraw said first kind of record medium from said printing station thereby to allow insertion of said second kind of record medium between said platen and said printhead, or is operable to feed said first kind

of record medium to said printing station, and that, when said platen arm is in said second position, said second roller means is operable to move either said first or said second kind of record medium out of said printing apparatus.

Brief Description of the Drawings

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a side view showing a portion of a printer in accordance with the present invention in an operating mode in which a receipt is printed; and

Fig. 2 is a side view similar to that of Fig. 1, showing the printer in a second mode of operation, in which a slip is being printed.

Best Mode for Carrying Out the Invention

As shown in Figs. 1 and 2, a printer 1 includes a printhead 20. A platen 16 is located in cooperative relation to the printhead 20 and is fixed to a first end of a movable platen arm 2 which is pivotally mounted on a shaft 9 in the printer. Also mounted on the platen arm 2 are a reversible motor 4 having a gear 10 driven by said motor, a second gear 12 rotatably mounted at a second end of the platen arm 2, and a third gear 14 rotatably mounted near the first end of the platen arm 2. As shown in Figs. 1 and 2, motion is transmitted to the gears 12 and 14 from the gear 10 by additional gears 30, 32, 34, 36 shown in phantom lines, though other transmission means such as pulleys and belts, or cooperating rollers, could be employed, if desired. A feed roller 6 is fixed to the same shaft as the gear 14 and * rotates therewith. A pusher roller 18 mounted in the printer framework opposite the feed roller 6 cooperates with the roller 6 for feeding of record

media when the platen arm 2 is in the position shown in Fig. 1. Movement of the platen arm 2 from the position in which it is shown in Fig. 2 to the position in which it is shown in Fig. 1 is accomplished by a solenoid 22 which is coupled to the platen arm 2 by a plunger 24.

When the platen arm 2 is'in the position in which it is shown in Fig. 2, the gear 12 on the platen arm 2 cooperates with a gear 13 journalled in the framework of the printer 1. A shift roller 8 is fixed on the same shaft as the gear 13 and rotates therewith. A roller 28 is journalled in the framework of the printer 1 and cooperates with the shift roller 8 to feed a continuous record medium 5 therebetween to or from a supply roll 3 contained within the printer depending on the direction of rotation of the motor 4. The record medium 5 may be printed upon by the printhead -20 and used for the issuance of a receipt to a customer in connection with a business transaction.

As will subsequently be described in greater detail, when the platen arm 2 is in the position shown in Fig. 2, the record medium 5 may be withdrawn from a position between the printhead 20 and the platen 16 by reverse rotation of the motor 4, and a slip 7, which may comprise a plurality of sheets, may be introduced from the exterior of the printer into a position between the platen 16 and the printhead 20 for printing thereon.

In the receipt printing mode, the receipt record medium 5 is led out to the opening 26 and the solenoid 22 is energized to push the plunger 24 upwardly and thereby rotate the platen arm 2, to which it is coupled, in a counterclockwise direction, from the position in which it is shown in Fig. 2 to the position in which it is shown in Fig. 1. Accordingly, the receipt record medium 5 is gripped between the feed roller 6 and the pusher roller 18 so that the

receipt record medium 5 can be freely fed by operating the motor 4 in accordance with the requirements of the printing operation.

The rotational motion of the motor 10 is also transmitted to the gear 12 simultaneously with its transmission to the gear 14, but produces no further effect at this time since the gear 12 is not operatively engaged with the-gear 13.

Now let it be assumed that the printer 1 is changed in operation from the receipt printing mode to the slip printing mode. The solenoid 22 is deenergized by a mode switch signal and the platen arm 2 rotates clockwise on the shaft 9 by its own weight, from the position shown in Fig. 1 to the position shown in Fig. 2 . Upon the clockwise rotation of the platen arm 2, the gear 12 engages with the gear 13, causing shift roller 8 to rotate in the rotating direction of the motor 4. The motor is caused to rotate in a direction to cause the cooperating shift roller 8 and roller 28 to take up the receipt record medium 5 on the roll '3. When the gear 12 first engages with the gear 13, the motor 4 may be rotated by a minute amount in order to enable the gears 12 and 13 to engage each other smoothly. The motor 4 stops after the receipt 5 is taken up by a predetermined amount.

Thereafter, the slip record medium 7 is inserted into the opening 26, as shown in Fig. 2, for performing of printing thereon. Before the printing operation is performed on the slip record medium 7, the solenoid 22 is energized to rotate the platen arm 2 in a counterclockwise direction. This causes the slip record medium 7 to be gripped and' held between the feed roller 6 and the pusher roller 18 so that a gap in proportion to the thickness of the slip record medium 7 is obtained between the printhead 20 and the platen 16.

After completion of printing on the slip record medium 7, and when it is desired to change to the receipt printing mode, the solenoid 22 is deenergized, as in the case of changing to the slip printing mode, to engage the gear 12 with the gear 13.

The motor 4 is then operated in a direction of rotation to cause the cooperating shift roller 8 and roller 28 to feed the receipt record medium 5 toward the print station. When the receipt record medium 5 reaches the print station, the motor 4 is stopped and waits a command for the printer to print out on the receipt record medium 5. When a printing signal is received the solenoid 22 is energized, as in the case of printing on the slip record medium 7, to rotate the platen arm 2 in a counterclockwise direction for a printing operation on the receipt record medium" 5.

In the illustrated embodiment, the weight of the platen arm 2 is utilized to obtain its clockwise rotation when the solenoid 22 is deenergized. Instead, if desired, elastic members such as springs or the like could be used.

As has been described above, in accordance with the present invention, a printer can provide the functions to perform the withdrawal and feeding of the continuous record medium, the switching of the roller driving means in accordance with the changing of a mode of printing, and the adjustment of the gap between the platen and the printhead in proportion to the thickness of the record medium by providing only a single operating means, as represented by the solenoid 22 and the platen arm 2 driven by the solenoid 22 in the illustrated embodiment.