Patent Description:
Conventionally, thermal printers that print on a print medium by thermal transfer are known (hereinafter simply referred to as "printers"). In such printers, a print medium is held in a pressurized state between a thermal head and a platen roller, and heating elements on the thermal head are selectively heated to print.

Some printers include a sheet holder, positioned near a printer unit in a body case for storing recording sheets, and a holder cover mounted on the sheet holder to be capable of opening and closing (e.g., <CIT>). By the printer unit having its lock member engaged with an engaging project of the holder cover, the holder cover is fixed when the printer unit is closed. Here, the platen roller keeps its rotary shaft being guided by guide parts; and a connection terminal part on the body case side and a connector formed by a contact electrode <NUM> on the holder cover side keep being coupled to each other.

However, in the holder cover of the printer in the Publication No. <CIT>, the distance from the holder cover's rotary shaft to the point where the engaging project engages with the lock member is about half as great as the distance from the holder cover's rotary shaft to the holder cover's tip. On the other hand, in the holder cover, the distance from the holder cover's rotary shaft to the connector is substantially equal to the distance from the holder cover's rotary shaft to the holder cover's tip. Accordingly, the distance from the point where the engaging project engages with the lock member to the connecter becomes about half as long as the distance from the holder cover's rotary shaft to the holder cover's tip. In other words, the distance from the holder cover's rotary shaft to the connector is approximately twice as great as the distance from the holder cover's rotary shaft to the point where the engaging project engages with the lock member.

Accordingly, even when the engaging project engages with the lock member, the connection can become unstable.

In addition, if the position of the engaging project engaging with the lock member deviates in the rotation direction of the holder cover, the position of the contact electrode will deviate about twice as much in the same direction. This may impair the secure connection of the connector.

An object of the present invention is to provide a printer with excellent connection between a first connector on the body side and a second connector on the openable printer cover side.

The present invention is a printer including the features of claim <NUM>.

An embodiment of the present invention improves the connection between the first connector on the body side and the second connector on the openable printer cover side.

In the following, a description will be given of embodiments of a printer of the present invention.

In the following, with reference to <FIG>, and <FIG>, a description will be given of a printer <NUM> according to an embodiment.

<FIG> is a perspective view of the printer <NUM> according to the embodiment showing its front, top, and left faces with its printer cover <NUM> closed. <FIG> is a perspective view of the printer <NUM> according to the embodiment showing its front, top, and left faces with its printer cover <NUM> open. <FIG> is a perspective view of the printer <NUM> according to the embodiment showing its upper and left faces.

As shown in <FIG>, and <FIG>, the printer <NUM> according to the present embodiment includes a body case <NUM>, a printer cover <NUM>, a display panel <NUM>, a platen roller <NUM>, and a thermal head <NUM> (an example of a "print head" of the present invention).

For example, as shown in <FIG>, an outer bottom surface <NUM> of the printer <NUM> (see <FIG>: an example of a printer bottom surface) is substantially rectangular, and the direction along its long side is defined as the front-rear direction. That is, it is defined that the side with the display panel <NUM> is the front (FR) and the opposite printer cover side is the rear (RR). A right side (RH), a left side (LH), a top side (UP), and a bottom side (LO) are defined relative to the front-rear direction. In the following description, as appropriate, the right (RH) or left (LH) direction is referred to as the lateral direction, and the top (UP) or bottom (LO) direction is referred to as the top-bottom direction.

As shown in <FIG>, the printer <NUM> may include a roll body accommodating chamber <NUM> for accommodating a roll body <NUM>, into which a continuous sheet (an example of a "print medium" of the present invention) <NUM> is wound. The body case <NUM> may include an inner bottom surface 2a (see <FIG>) for the roll body <NUM> to be placed on. The continuous sheet <NUM> includes a mount and a plurality of labels tentatively attached to the mount.

The printer cover <NUM> is a cover that opens or shuts off the inside of the printer <NUM>. A hinge <NUM>, including a hinge shaft <NUM>, is provided at the rear end of the printer cover <NUM>. The hinge <NUM> rotatably holds the printer cover <NUM> to be rearwardly openable relative to the body case.

As will be described later, the hinge <NUM> is slidable in the front-rear direction.

The display panel <NUM> functions as an input/output interface for the user, and is a liquid crystal display panel with the touchscreen function, for example.

As shown in <FIG>, a platen roller <NUM> is provided at the tip side of the printer cover <NUM>, opposite to the side where the hinge <NUM> is, to be rotatable in the forward and reverse directions. As shown in <FIG>, when the printer cover <NUM> is closed, the platen roller <NUM> is disposed behind the thermal head <NUM>.

The platen roller <NUM> is conveying means for conveying the continuous sheet <NUM> drawn out of the roll body <NUM>, which is accommodated in the roll body accommodating chamber <NUM> while retained by a pair of roll body guides 6a. The platen roller <NUM> extends along the width direction of the roll body <NUM>. The platen roller <NUM> is mechanically coupled to a stepping motor (not shown) or the like to be driven.

The thermal head <NUM> is printing means that prints information such as characters, symbols, graphics, or barcodes on the continuous sheet <NUM> drawn out of the roll body <NUM>. As shown in <FIG>, when the printer cover <NUM> is closed, the printing surface of the thermal head <NUM> faces the feed route of the continuous sheet <NUM> and is opposed to the platen roller <NUM>. A plurality of heat elements (not shown) that generate heat when energized are arranged on the printing surface of the thermal head <NUM> along the width direction of the continuous sheet <NUM>. The thermal head <NUM> is connected to a circuit board (not shown) that transmits printing signals to the thermal head <NUM>.

On the back side of the thermal head <NUM>, a coil spring <NUM> as a biasing member is provided for providing biasing force to the thermal head <NUM>.

When the printer cover <NUM> is closed and printing is carried out, the continuous sheet <NUM> is pinched between the platen roller <NUM> and the thermal head <NUM> while conveyed by the platen roller <NUM>. Here, the thermal head <NUM> is pressed against the platen roller <NUM> with the biasing force, thereby generating a head pressure suitable for printing.

Around the roll body accommodating chamber <NUM> in the rear half of the printer <NUM>, the body case <NUM> includes a portion that covers the lower half space of the roll body accommodating chamber <NUM> on the right and left sides and from behind and below, and a portion that covers the space accommodating mechanisms and circuitry in the front half of the printer <NUM> on the right and left sides and from the front, below, and above.

Around the roll body accommodating chamber <NUM>, the printer cover <NUM> covers the upper half space of the roll body accommodating chamber <NUM> on the right and left sides and from behind and above.

The printer cover <NUM> can be opened and closed about the rotary shaft of the hinge <NUM> between the closed position shown in <FIG> and the open position at the maximum open angle shown in <FIG>. Here, the maximum open angle refers to an angle at which the printer cover <NUM> cannot further be rotated by cover-side buffer members <NUM> (see <FIG> and <FIG>) provided at a rear surface part <NUM> of the printer cover <NUM>. At the maximum open angle, the cover-side buffer members <NUM> abut on body-side buffer members <NUM> (see <FIG> and <FIG>) provided at a rear surface part <NUM> of the body case <NUM>.

In an embodiment, as shown in <FIG>, the printer cover <NUM> has a two-layer structure made up of an inner printer cover <NUM> and an outer printer cover <NUM> in view of strength. The present invention is not limited to such a structure.

As shown in <FIG>, when the outer printer cover <NUM> and the inner printer cover <NUM> are separated from each other, the platen roller <NUM> can be held on a tentative-retaining part <NUM> provided at the outer printer cover <NUM>. A pair of shaft-supporting members <NUM> are provided at the both ends of a platen shaft 10a.

<FIG> shows a cross section, perpendicular to the platen shaft 10a, of the printer cover <NUM> in which the outer printer cover <NUM> and the inner printer cover <NUM> are integrated by being screwed to each other at the shaft-supporting members <NUM>.

As shown in <FIG>, the pair of shaft-supporting members <NUM> are each interposed between a shaft-supporting member retaining part 37a provided on the inner side of the outer printer cover <NUM> and a shaft-supporting member retaining part 36b provided on the outer side of the inner printer cover <NUM>. Thus, when the outer printer cover <NUM> and the inner printer cover <NUM> are screwed to each other to be the integrated printer cover <NUM>, the platen shaft 10a is rotatably fixed to the printer cover <NUM>.

As shown in <FIG>, the body case <NUM> includes a pair of platen shaft retaining portions <NUM>. The pair of platen shaft retaining portions <NUM> are provided at substantially the right and left ends (one example of a second position) for retaining the platen shaft 10a at the tip of the printer cover <NUM> when the printer cover <NUM> is at the closed position. The platen shaft retaining portions <NUM> are formed at the body frame of the body case <NUM>.

Specifically, the pair of platen shaft retaining portions <NUM> respectively rotatably retain a pair of first retained portions 10c (see <FIG>; an example of a second portion of the platen roller) at substantially the right and left ends of the platen shaft 10a when the printer cover <NUM> is at the closed position.

As shown in <FIG>, particularly, front end surfaces and rear end surfaces of the first retained portions 10c of the platen shaft 10a abut on vertical surfaces of a front wall 26d and a rear wall 26e of each of the platen shaft retaining portions <NUM>. This restricts the platen shaft 10a from shifting in the front-rear direction. The vertical surfaces may be surfaces perpendicular to the outer bottom surface <NUM>. However, the surfaces formed at the front wall 26d and the rear wall 26e are not specified to the vertical surfaces, and may be any surfaces that are opposed to each other for retaining the first retained portions 10c of the platen shaft 10a.

<FIG> is a perspective view of the printer <NUM> showing the platen shaft retaining part <NUM> provided substantially at the right end of the body case <NUM>.

As shown in <FIG>, a pair of arms <NUM> (an example of a platen retaining part) are provided at substantially the right and left ends of a platen retaining bracket <NUM>. As shown in <FIG>, the platen retaining bracket <NUM> includes the pair of arms <NUM> and a beam <NUM> coupling them to each other. The beam <NUM> includes a hook 27i for suspending a coil spring <NUM>. The pair of arms <NUM> include holes 27j for a rotary shaft 27a to pass through. While not shown in the drawings, the rotary shaft 27a is inserted through the body frame of the body case <NUM>.

Accordingly, the platen retaining bracket <NUM> can rotate so that the pair of arms <NUM> tilt in the front-rear direction about the rotary shaft 27a. Here, the coil spring <NUM> biases the platen retaining bracket <NUM> in a direction in which the pair of arms <NUM> tilt frontward (a direction toward which an elevation angle θ becomes smaller (see <FIG>)).

As shown in <FIG>, each arm <NUM> includes an upper holding portion 27d and a lower holding portion 27e in an order from the far side of distance from the rotary shaft 27a. A holding portion groove 27b is formed between the upper holding portion 27d and the lower holding portion 27e.

As shown in <FIG>, the right platen shaft retaining part <NUM> is provided at substantially the right end of the body case <NUM>. The right arm <NUM> is provided adjacent to and toward the center than the right platen shaft retaining part <NUM>. Similarly, while not shown, the left platen shaft retaining part <NUM> is provided at substantially the left end. The left arm <NUM> is provided adjacent to and toward the center than the left platen shaft retaining part <NUM>.

As shown in <FIG>, when the printer cover <NUM> is at the closed position, a lower surface (an upward-displacement preventing surface) <NUM> of the upper holding portion 27d of each arm <NUM> of the platen retaining bracket <NUM> is in contact with the upper end surface of a portion as a second retained portion 10d (see <FIG>; an example of a first portion of the platen roller) of the platen shaft 10a. When the printer cover <NUM> is at the closed position, an upper surface (a downward-displacement preventing surface) 27p of the lower holding portion 27e of each arm <NUM> of the platen retaining bracket <NUM> is in contact with the lower end surface of the portion as the second retained portion 10d (see <FIG>) of the platen shaft 10a. Accordingly, when the printer cover <NUM> is at the closed position, the upward-displacement preventing surface <NUM> and the downward-displacement preventing surface 27p restrict the second retained portions 10d of the platen shaft 10a from shifting in the top-bottom direction.

That is, in <FIG>, there are provided a pair of surfaces (namely, the upward-displacement preventing surface <NUM> and the downward-displacement preventing surface 27p) for restricting the clockwise and counterclockwise circular movement of the second retained portions 10d of the platen roller <NUM> upon the swinging movement of the printer cover <NUM>. The upper holding portion 27d, the lower holding portion 27e, and the holding portion groove 27b prevent the platen roller <NUM> from swinging and shifting by a predetermined distance or longer from an engaged position (a position Q (x1, y1, z1), which will be described later). Thus, the platen roller <NUM> is surely retained.

With reference to <FIG>, a first retained portion 10c is located near one end of the platen shaft 10a and the corresponding second retained portion 10d is farther from the end (i.e., nearer to the center). The vertical surfaces of the front wall 26d and rear wall 26e of the platen shaft retaining part <NUM> abut on the corresponding first retained portion 10c. The upward-displacement preventing surface <NUM> and the downward-displacement preventing surface 27p are in contact with the corresponding second retained portion 10d. The same applies to the other end of the platen shaft 10a.

Accordingly, as shown in an enlarged manner in <FIG>, when the printer cover <NUM> is at the closed position, the shift of the platen shaft 10a is limited from four sides by four surfaces, namely, the vertical surface of the front wall 26d and the vertical surface of the rear wall 26e of each platen shaft retaining part <NUM>, and the upward-displacement preventing surface <NUM> and the downward-displacement preventing surface 27p of the platen retaining bracket <NUM>.

When the printer cover <NUM> is at the open position, an elevation angle θ of the arms <NUM> is a minimum elevation angle θ1 (see <FIG>). During the shifting of the printer cover <NUM> from the open position toward the closed position, the platen shaft 10a abuts on the upper surface 27f. When the printer cover <NUM> is further brought closer to the closed position, since the upper surface 27f inclined relative to the radial direction of the arms <NUM> is pushed by the platen shaft 10a, the elevation angle θ of the arms <NUM> becomes gradually greater. When the platen shaft 10a passes through tips 27n of the arms <NUM>, the elevation angle θ of the arms <NUM> becomes a maximum elevation angle θ2. When the printer cover <NUM> is further brought closer to the closed position, the platen shaft 10a gradually shifts to be located under the tips 27n of the arms <NUM>, and the arms <NUM> rotate by the biasing force of the coil spring <NUM> in the direction in which the elevation angle θ decreases while maintaining the contact between the platen shaft 10a and the tips 27n. When the platen shaft 10a shifts to be located under the upward-displacement preventing surface <NUM>, the elevation angle θ of the arms <NUM> becomes the minimum elevation angle θ1. At this time, the platen shaft 10a is restricted from shifting upward by the upward-displacement preventing surface <NUM> and from shifting downward by the downward-displacement preventing surface 27p. In this state of the platen shaft 10a, the platen shaft 10a is locked by the arms <NUM> and the printer cover <NUM> is closed at the closed position.

In order to cancel the lock, the user operates a cover releasing button 51b so that the arms <NUM> swing to increase the elevation angle θ of the arms <NUM> against the resilience of the coil spring <NUM>. Thus, due to the biasing force of the hinge <NUM>, the printer cover <NUM> swings toward the open position and the platen shaft 10a is released from the holding portion groove 27b.

As shown in <FIG> and <FIG>, the hinge <NUM> extends in the lateral direction at an upper peripheral portion <NUM> of the rear surface part <NUM> of the body case <NUM>.

A lower peripheral portion <NUM> of the rear surface part <NUM> of the printer cover <NUM> is coupled via the hinge <NUM> to the upper peripheral portion <NUM> of the rear surface part <NUM> of the body case <NUM> so that the hinge <NUM> allows the printer cover <NUM> to open and close.

As shown in <FIG>, the hinge <NUM> includes the hinge shaft <NUM>, body-side shaft-supporting long holes <NUM>, inner printer cover-side shaft-supporting round holes <NUM>, outer printer cover-side shaft-supporting round holes <NUM>, and a torsion spring <NUM>.

The pair of body-side shaft-supporting long holes <NUM> are provided at the right and left ends near the rear end of the roll body accommodating chamber <NUM>. The body-side shaft-supporting long holes <NUM> have a long axis in the front-rear direction. Here, the long axis direction of the body-side shaft-supporting long holes <NUM> may be slightly displaced from the front-rear direction.

The pair of inner printer cover-side shaft-supporting round holes <NUM> are provided at the rear end of the inner printer cover <NUM>.

The pair of outer printer cover-side shaft-supporting round holes <NUM> are provided at the rear end of the outer printer cover <NUM>.

The hinge shaft <NUM> is inserted through the pair of inner printer cover-side shaft-supporting round holes <NUM> and the pair of outer printer cover-side shaft-supporting round holes <NUM>. The hinge shaft <NUM> has its both ends inserted into the pair of body-side shaft-supporting long holes <NUM>.

The hinge shaft <NUM> (an example of a rotary shaft) extends in the lateral direction at the upper peripheral portion <NUM> (see <FIG>) of the rear surface part <NUM> of the body case <NUM>. Accordingly, the body-side shaft-supporting long holes <NUM>, the inner printer cover-side shaft-supporting round holes <NUM>, and the outer printer cover-side shaft-supporting round holes <NUM> are also provided at the upper peripheral portion <NUM> of the rear surface part <NUM> of the body case <NUM>. Accordingly, in the printer cover <NUM>, the inner printer cover-side shaft-supporting round holes <NUM> and the outer printer cover-side shaft-supporting round holes <NUM> are positioned lower than the horizontal boundary line <NUM> (see <FIG>) between the body case <NUM> and the printer cover <NUM>.

In operation, the inner printer cover <NUM> and the outer printer cover <NUM> are integrated by being screwed to each other. When the inner printer cover <NUM> and the outer printer cover <NUM> are screwed to each other, the inner printer cover <NUM> and the outer printer cover <NUM> can rotate about the hinge shaft <NUM> while being integrated. On the other hand, when the inner printer cover <NUM> and the outer printer cover <NUM> are not screwed to each other, they can separately rotate about the hinge shaft <NUM>. <FIG> shows the inner printer cover <NUM> and the outer printer cover <NUM> integrated by being screwed to each other. <FIG> shows the inner printer cover <NUM> and the outer printer cover <NUM> not screwed but separate from each other.

Accordingly, when the hinge shaft <NUM> slides in the front-rear direction, the integrated inner printer cover <NUM> and the outer printer cover <NUM> slide together in the front-rear direction. That is, when the hinge shaft <NUM> slides in the front-rear direction, the printer cover <NUM> slides in the front-rear direction.

The integrated inner printer cover <NUM> and outer printer cover <NUM> can rotate together about the hinge shaft <NUM>. That is, the printer cover <NUM> can rotate about the hinge shaft <NUM>.

The torsion spring <NUM> biases the printer cover <NUM> to open the printer cover <NUM> in the closed state.

The body-side shaft-supporting long holes <NUM> whose long axes are elongated in the front-rear direction allows the hinge shaft <NUM> of the hinge shaft <NUM> to slide in the front-rear direction. That is, the hinge shaft <NUM> can slide in the direction perpendicular to the hinge shaft <NUM> within a horizontal plane.

<FIG> shows the motion of the platen shaft 10a when the printer cover <NUM> is closed. In <FIG>, positions B22, B23, and B24 correspond to the center position of the platen shaft 10a, and loci S20, S23, and S24 correspond to the locus of the center position of the platen shaft 10a.

With reference to <FIG>, when the hinge shaft <NUM> is at the position A1 at the rear end (see <FIG>) (i.e., when the hinge shaft <NUM> is at the rear end of the body-side shaft-supporting long holes <NUM>), in a process of the printer cover <NUM> transitioning from the open state to the closed state, the platen shaft 10a moves in a circular motion through the locus S20 in accordance with the swing of the printer cover <NUM>. At the position B22, the platen shaft 10a is brought into contact with the rear walls 26e of the platen shaft retaining portions <NUM>. Thereafter, since the hinge shaft <NUM> is capable of sliding in the front-rear direction between the position A1 and the position A2 at the front end (see <FIG>) in the body-side shaft-supporting long holes <NUM>, the platen shaft 10a passes the locus S23 while keeping the contact with the rear walls 26e to reach the position B23. After reaching the position B23, the platen shaft 10a passes along the front walls 26d and the vertical surface of the rear walls 26e of the platen shaft retaining portions <NUM> to reach the position B24. When the platen shaft 10a is at the position B24, the platen shaft 10a substantially reaches bottom portions 26c and the printer cover <NUM> enters the closed state. Here, the first retained portions 10c of the platen shaft 10a are interposed and held between the vertical surfaces of the front walls 26d and the vertical surfaces of the rear walls 26e.

Immediately before the printer cover <NUM> enters the closed state, the platen shaft 10a moves straight in the top-bottom direction along the locus B24, and accordingly, a cover-side connector <NUM> attached to the printer cover <NUM> moves in the top-bottom direction with the platen shaft 10a. As a result, cover-side connector male terminals <NUM> of the cover-side connector <NUM> are straightly brought into contact with body-side connector female terminals <NUM> of a body-side connector <NUM>, thereby significantly reducing risk of any contact failure.

Provided that the hinge shaft <NUM> cannot slide in the front-rear direction, the platen shaft 10a cannot pass along the locus S23 and, accordingly, the platen shaft 10a cannot reach the bottom part 26c. By virtue of the body-side shaft-supporting long holes <NUM> allowing the hinge shaft <NUM> to slide in the front-rear direction, the platen shaft 10a is capable of reaching the bottom part 26c.

Note that, when the printer cover <NUM> has an integral structure instead of the two-layer structure made up of the inner printer cover <NUM> and the outer printer cover <NUM>, a single pair of right and left printer cover-side shaft-supporting round holes will suffice.

As shown in <FIG>, a plurality of body-side buffer members <NUM> are arranged in the lateral direction on the rear surface part <NUM> of the body case <NUM>. In the embodiment in <FIG>, three body-side buffer members <NUM> are arranged in the lateral direction on each of the right and left sides of the rear surface part <NUM> of the body case <NUM>.

Similarly, a plurality of cover-side buffer members <NUM> are arranged in the lateral direction on the rear surface part <NUM> of the printer cover <NUM>. In the embodiment in <FIG>, three cover-side buffer members <NUM> are arranged in the lateral direction of each of the right and left sides of the rear surface part <NUM> of the printer cover <NUM>.

In an embodiment, as shown in <FIG>, the body-side buffer members <NUM> and the cover-side buffer members <NUM> may form pairs in the identical positions in the lateral direction.

In the embodiment shown in <FIG>, the body-side buffer members <NUM> each include a total of five surfaces, i.e., a tip surface <NUM> and four side surfaces. Similarly, the cover-side buffer members <NUM> each include a total of five surfaces, i.e., a tip surface <NUM> and four side surfaces. This is merely an example and the shape of the surfaces of the body-side buffer members <NUM> and the cover-side buffer members <NUM> may be designed as appropriate.

As shown in <FIG>, <FIG>, and <FIG>, the body-side connector <NUM> is provided at a body-side connector placement part <NUM> (an example of a first position) and the cover-side connector <NUM> is provided at a cover-side connector placement part <NUM>.

As shown in <FIG>, when the printer cover <NUM> is at the closed position, the body-side connector female terminals <NUM> of the body-side connector <NUM> and the cover-side connector male terminals <NUM> of the cover-side connector <NUM> are brought into contact with each other. The contacts between six body-side connector female terminals <NUM> and cover-side connector male terminals <NUM> are on one virtual plane that is parallel to the outer bottom surface <NUM> of the printer <NUM>.

With reference to <FIG> and <FIG>, the body-side connector <NUM> (an example of a first connector) provided at the body-side connector placement part <NUM> is structured as follows.

A body-side connector first recessed part <NUM> is provided at a body-side connector abutting surface <NUM> (an example of a first abutting surface). Inside the body-side connector first recessed part <NUM>, six body-side connector second recesses <NUM> arranged in a <NUM>×<NUM> matrix are provided. The body-side connector female terminals <NUM> are disposed at the bottom portion of the body-side connector second recesses <NUM>, respectively.

A pair of lateral projecting portions <NUM> are provided on both sides of the body-side connector abutting surface <NUM>. The body-side connector abutting surface <NUM> is parallel to the outer bottom surface <NUM> of the printer <NUM>.

With reference to <FIG> and <FIG>, the cover-side connector <NUM> (an example of a second connector) provided at the inner printer cover <NUM> is structured as follows.

At a cover-side connector abutting surface <NUM> (an example of a second abutting surface), six cover-side connector male terminals <NUM> arranged in a <NUM>×<NUM> matrix are provided. When the printer cover <NUM> is at the closed position, the cover-side connector abutting surface <NUM> is parallel to the outer bottom surface <NUM> of the printer <NUM>.

A pair of lateral grooves <NUM> are provided on both sides of the cover-side connector abutting surface <NUM>.

When the printer cover <NUM> is closed, the six body-side connector female terminals <NUM> and the six cover-side connector male terminals <NUM> have their corresponding terminals brought into contact with each other.

As shown in <FIG> also, when the printer cover <NUM> is closed, the cover-side connector abutting surface <NUM> abuts on the body-side connector abutting surface <NUM>.

The pair of lateral grooves <NUM> engage with the pair of lateral projecting portions <NUM>. This engagement hardly permits ingress of liquid such as water to the region between the lateral grooves <NUM> and the lateral projecting portions <NUM>. Since the pair of lateral grooves <NUM> and the pair of lateral projecting portions <NUM> extend in the front-rear direction, the engagement prevents the body-side connector abutting surface <NUM> from sliding in the lateral direction relative to the cover-side connector abutting surface <NUM>. Accordingly, the cover-side connector male terminals <NUM> are prevented from sliding in the lateral direction relative to corresponding ones of the body-side connector female terminals <NUM>.

In another embodiment, the lateral grooves may be provided at the body-side connector <NUM> and the lateral projecting portions may be provided at the cover-side connector <NUM>.

With reference to <FIG>, the cover-side connector male terminals <NUM> have portions exposed (projected) outside the cover-side connector abutting surface <NUM> and portions not exposed. <FIG> shows only the portions of the cover-side connector male terminals <NUM> that are exposed (projected) outside the cover-side connector abutting surface <NUM>.

The cover-side connector male terminals <NUM> are embedded in a cover-side connector male terminal basal part <NUM>, which is cylindrical and greater in diameter than the cover-side connector male terminals <NUM>, in such a manner that the cover-side connector male terminals <NUM> can be displaced in the axial direction within a predetermined range relative to the cover-side connector male terminal basal part <NUM> as shown in <FIG>.

The cover-side connector male terminal basal part <NUM> is fixed to the outer printer cover <NUM> via a fixing member <NUM>.

With reference to <FIG>, a length D (the predetermined range) of the portions projecting frontward relative to the cover-side connector abutting surface <NUM> ranges from a Dmim (minimum length) in a state S1 to a Dmax (maximum length) in a state S3. The cover-side connector male terminals <NUM> are biased by a spring (not shown), for example, in the direction of increasing the length D of the portions projecting frontward relative to the cover-side connector abutting surface <NUM>.

When the printer cover <NUM> is open, the cover-side connector male terminals <NUM> are in the state S3, where length D = Dmax. When the printer cover <NUM> is closed, the cover-side connector male terminals <NUM> are in a state S2, in which the length of the portions projecting frontward relative to the cover-side connector abutting surface <NUM> is defined as Dstd. The length Dstd is a length measured when the printer cover <NUM> is closed and the cover-side connector abutting surface <NUM> abuts on the body-side connector abutting surface <NUM>. Here,a relation of Dmim < Dstd < Dmax is satisfied. Preferably, Dstd substantially equals to (Dmim + Dmax)/<NUM> (that is, Dstd≈ (Dmim + Dmax)/<NUM>).

The length D when the printer cover <NUM> is open is Dmax. In the process of the printer cover <NUM> transitioning from the open state to the closed state, the cover-side connector male terminals <NUM> reach the body-side connector female terminals <NUM>. At this time, the cover-side connector abutting surface <NUM> is yet to reach the body-side connector abutting surface <NUM>.

As the cover-side connector abutting surface <NUM> is becoming closer to the body-side connector abutting surface <NUM>, the length D becomes gradually shorter. When the cover-side connector abutting surface <NUM> reaches the body-side connector abutting surface <NUM>, the length D becomes Dstd.

With reference to <FIG> and <FIG>, in an embodiment, the body-side connector placement part <NUM> is adjacent to the rear (RR) of the platen shaft retaining portions <NUM> and to the rear (RR) of the arms <NUM>, in the front-rear direction. In the lateral direction, the body-side connector placement part <NUM> is at the position substantially identical to the platen shaft retaining portions <NUM> and adjacent to the left side (LH) (i.e., the outer side) of the arms <NUM>. In the top-bottom direction, the body-side connector placement part <NUM> is at the height substantially identical to the bottom part 26c of the platen shaft retaining portions <NUM>.

The body-side connector placement part <NUM> is integrated with the body frame. In particular, the body-side connector abutting surface <NUM> and the pair of lateral projecting portions <NUM> are formed as part of the body frame.

A magnet may be disposed in the vicinity of both of the body-side connector <NUM> and the cover-side connector <NUM>. Alternatively, a magnetic may be disposed near one of the connectors <NUM>, <NUM> and a ferromagnetic element may be disposed in the vicinity of the other one of the connectors <NUM>, <NUM>. In such structures, after the body-side connector <NUM> and the cover-side connector <NUM> becomes close to each other, they will attract each other by magnetism, thereby ensuring the connection therebetween.

When the printer cover <NUM> is at the closed position, the platen shaft 10a has its position defined from four sides, namely, the top, bottom, front, and rear sides, by the platen shaft retaining portions <NUM> and the platen retaining bracket <NUM>. Accordingly, the body-side connector <NUM> is positioned precisely relative to the platen shaft 10a.

On the other hand, as described with reference to <FIG>, the fixing member <NUM> that fixes the cover-side connector male terminal basal part <NUM> is fixed to the outer printer cover <NUM>, and the cover-side connector abutting surface <NUM> is a portion of the outer surface of the outer printer cover <NUM>. The platen shaft 10a is rotatably fixed to the printer cover <NUM>. Accordingly, in the printer cover <NUM>, the cover-side connector <NUM> is positioned precisely relative to the platen shaft 10a.

Thus, in the printer <NUM>, the body-side connector <NUM> and the cover-side connector <NUM> are positioned precisely relative to each other when the printer cover <NUM> is closed.

As has been described above, when the printer cover <NUM> is closed, the platen shaft 10a has its position defined from four sides, namely, the top, bottom, front, and rear sides, by the platen shaft retaining portions <NUM> and the platen retaining bracket <NUM>. Thus, the body-side connector <NUM> and the cover-side connector <NUM> are positioned precisely relative to each other. As a result, the connection between the body-side connector female terminals <NUM> and the cover-side connector male terminals <NUM> is improved.

In another aspect, as shown in <FIG> and <FIG>, in the printer <NUM>, the position (an example of a first position) where the body-side connector placement part <NUM> is provided is disposed close to, preferably adjacent to, the position (an example of a second position) where the platen retaining bracket <NUM> retains the second retained portion 10d of the platen shaft 10a. Thus, the contact position between the body-side connector <NUM> and the cover-side connector <NUM> becomes close to the position where the second retained portion 10d of the platen shaft 10a is retained. This prevents any misalignment of the contact position and improves the connection stability between the connectors.

In <FIG>, the front-rear direction of the printer <NUM> is defined as follows: the front side is where the platen roller <NUM> is, as seen from the direction perpendicular to the outer bottom surface <NUM> when the printer cover <NUM> is closed; and the rear side is where the hinge <NUM> (or the hinge shaft <NUM>) is.

As shown in <FIG>, the position where the body-side connector placement part <NUM> is provided is positioned between the position where the platen retaining bracket <NUM> retains the second retained portion 10d of the platen shaft 10a and the hinge shaft <NUM> in the front-rear direction of the printer <NUM> when the printer cover is closed.

Here, as described above, the displacement of the second retained portions 10d of the platen shaft 10a in the top-bottom direction is restricted by the platen retaining bracket <NUM>. This improves the connection stability between the body-side connector <NUM>, which is positioned between the second retained portion 10d of the platen shaft 10a and the hinge shaft <NUM> in the front-rear direction, and the cover-side connector <NUM>, which is fixed to the printer cover <NUM> on which the platen shaft 10a is mounted.

That is, in the printer <NUM>, by virtue of the contact between the connectors being disposed between the hinge position and the lock position of the printer cover and the body case, the connection stability is improved. If the contact between the connectors was not positioned between the hinge position and the lock position, distortion in the body case or displacement of the lock position would likely result in misalignment of the contact position.

When the body-side connector <NUM> and the cover-side connector <NUM> are disconnected from each other while the printer <NUM> is carried, the settings of a position-detecting sensor <NUM> and a label sensor <NUM> are cleared. Therefore, the connection stability between the body-side connector <NUM> and the cover-side connector <NUM> is important.

With reference to <FIG>, the body-side connector female terminals <NUM>-<NUM> to <NUM>-<NUM> are connected to a body-side circuit <NUM>. A power supply <NUM> is connected to the body-side circuit <NUM>.

Among six sets of body-side connector female terminals <NUM>-<NUM> to <NUM>-<NUM> and cover-side connector male terminals <NUM>-<NUM> to <NUM>-<NUM>, the first and second sets of body-side connector female terminals <NUM>-<NUM>, <NUM>-<NUM> and cover-side connector male terminals <NUM>-<NUM>, <NUM>-<NUM> correspond to the light-reflection type position-detecting sensor <NUM>. The light-reflection type position-detecting sensor <NUM> emits light toward the continuous sheet <NUM>, and detects black position detection marks on the continuous sheet <NUM> based on the intensity of reflective light from the continuous sheet <NUM>. A first set of cover-side connector male terminal <NUM>-<NUM> and a second set of cover-side connector male terminal <NUM>-<NUM> are connected to the position-detecting sensor <NUM> via onboard wires <NUM>-<NUM>, <NUM>-<NUM> of a flexible board <NUM>, respectively.

Third and fourth sets of body-side connector female terminals <NUM>-<NUM>, <NUM>-<NUM> and cover-side connector male terminals <NUM>-<NUM>, <NUM>-<NUM> correspond to the light-transmission type label sensor <NUM>. The light-transmission type label sensor <NUM> detects the labels on the continuous sheet <NUM> based on the intensity of light received from a light emitting device <NUM> via an emitting-side optical filter <NUM>, the continuous sheet <NUM>, and a receiving-side optical filter <NUM>. The third set of cover-side connector male terminal <NUM>-<NUM> and the fourth set of cover-side connector male terminal <NUM>-<NUM> are connected to the label sensor <NUM> via onboard wires <NUM>-<NUM>, <NUM>-<NUM> of the flexible board <NUM>, respectively.

Fifth and sixth sets of body-side connector female terminals <NUM>-<NUM>, <NUM>-<NUM> and cover-side connector male terminals <NUM>-<NUM>, <NUM>-<NUM> are provided for detecting whether the printer cover <NUM> is open or closed. The fifth set of cover-side connector male terminal <NUM>-<NUM> and the sixth set of cover-side connector male terminal <NUM>-<NUM> are short-circuited by an onboard wire <NUM>-<NUM> of the flexible board <NUM>.

The sixth set of body-side connector female terminal <NUM>-<NUM> and cover-side connector male terminal <NUM>-<NUM> correspond to a ground line.

With reference to <FIG>, a continuous sheet path front surface 9a and a continuous sheet path rear surface 36a are provided at the body and the inner printer cover <NUM>, respectively. When the printer cover <NUM> is closed, the continuous sheet path front surface 9a and the continuous sheet path rear surface 36a form a path for the continuous sheet <NUM> to pass through immediately before reaching the platen roller <NUM> and the thermal head <NUM>.

The continuous sheet path front surface 9a and the continuous sheet path rear surface 36a are provided with the emitting-side optical filter <NUM> and the receiving-side optical filter <NUM>, respectively. When the printer cover <NUM> is closed, the emitting-side optical filter <NUM> and the receiving-side optical filter <NUM> face each other while the continuous sheet <NUM>, which is conveyed from the roll body <NUM> to the thermal head <NUM>, is interposed between the filters.

The light emitting device <NUM> is disposed on the inner surface side of the emitting-side optical filter <NUM>. As shown in <FIG>, a sensor-dedicated board <NUM> equipped with the label sensor <NUM> is disposed on the back side of the continuous sheet path rear surface 36a. When the printer cover <NUM> is closed, the label sensor <NUM> is opposed to the light emitting device <NUM>.

As shown in <FIG>, the flexible board <NUM> is connected to the cover-side connector male terminals <NUM> (not visible in <FIG>) in the cover-side connector placement part <NUM>. The flexible board <NUM> is connected to the sensor-dedicated board <NUM> via the periphery of the inner surface (the surface opposed to the outer printer cover <NUM>) of the inner printer cover <NUM>.

With reference to <FIG> again, when the printer cover <NUM> is open, the body-side connector female terminals <NUM> are exposed. The body-side connector female terminals <NUM> is connected to the body-side circuit <NUM> supplied with power from the power supply <NUM>. Here, the body-side connector female terminals <NUM> is in a recessed position relative to the body-side connector abutting surface <NUM>. That is, the tips of the body-side connector female terminals <NUM> brought into contact with the cover-side connector male terminals <NUM> are positioned in the body-side connector second recesses <NUM>. This prevents electrostatic discharge that would otherwise occur by the user accidentally touching the body-side connector female terminals <NUM>.

When the printer cover <NUM> is open, the user may accidentally touch the cover-side connector male terminals <NUM>. Here, when the printer cover <NUM> is open, the position-detecting sensor <NUM> and the label sensor <NUM> connected to the cover-side connector male terminals <NUM> are not supplied with power. This prevents any possible damage to these electronic components due to electrostatic discharge or the like.

While the body-side connector has female terminals and the cover-side connector has male terminals in the illustrated embodiment, the present invention is not limited thereto. The body-side connector may have male terminals and the cover-side connector may have female terminals.

In conventional printers, a sensor at a printer cover and an electronic circuit at a body case are connected by a cable that passes near a hinge that rotatably connects the printer cover to the body case. Thus, the cable is flexed every time the printer cover is opened or closed, which increases risk of breakage of the cable. Besides, since the electronic circuit and the sensor are kept being electrically connected when the printer cover is opened or closed, the electrical connection may be disturbed. Furthermore, dedicated components for wiring the cable must be separately prepared and wired with some burden. These problems are obstacle in replacing the printer cover.

In contrast, the printer <NUM> according to the present embodiment does not employ such a cable that passes near the hinge <NUM> that rotatably connects the printer cover <NUM> to the body case <NUM>. Accordingly, there will be no breakage of a cable due to the opening or closing operation of the printer cover. Furthermore, this eliminates the necessity of separately preparing the component for wiring the cable. Without any burden in wiring the cable, the printer cover <NUM> can be replaced with ease.

When the printer cover <NUM> is open, none of the position-detecting sensor <NUM> and the label sensor <NUM> and other circuit components at the printer cover <NUM> are electrically connected to the body-side circuit <NUM> (an example of a circuit connected to a power supply). This prevents electric troubles such as discharging by these electronic components at the printer cover <NUM> when the printer cover <NUM> is open.

As shown in <FIG>, the platen roller <NUM> in printing is biased rearward by the coil spring <NUM> via the thermal head <NUM> and the print medium. The biasing direction of the coil spring <NUM> is the front-rear direction of the printer <NUM>. Here, as shown in <FIG>, since the platen shaft 10a is supported from behind by the rear walls 26e of the platen shaft retaining portions <NUM>, the platen shaft 10a is prevented from being displaced rearward.

The engagement between the lateral projecting portions <NUM> and the lateral grooves <NUM> is maintained. Therefore, while being restricted from shifting in the lateral direction relative to the body-side connector abutting surface <NUM>, the cover-side connector abutting surface <NUM> can shift in the front-rear direction. Even if the platen shaft 10a slightly shifts in the front-rear direction, the contact between the connectors is maintained while the cover-side connector abutting surface <NUM> slides in the front-rear direction on the body-side connector abutting surface <NUM>.

Furthermore, even when the distance from the body-side connector abutting surface <NUM> to the cover-side connector abutting surface <NUM> varies due to variations in the position or attitude of the platen roller <NUM> in the front-rear direction, the connection between the body-side connector <NUM> and the cover-side connector <NUM> is maintained well. That is, as shown in <FIG>, the cover-side connector male terminals <NUM> are biased in the direction of increasing the length of the portions projecting frontward relative to the cover-side connector abutting surface <NUM>. Since a change in the projecting length of the cover-side connector male terminals <NUM> absorbs the distance variations, the contact between the body-side connector female terminals <NUM> and the cover-side connector male terminals <NUM> is maintained well.

Next, the shock-absorption property will be discussed.

As shown in <FIG>, when any shock (external force F) is applied to the printer cover <NUM> from outside, the hinge shaft <NUM> may deform to slide along the body-side shaft-supporting long holes <NUM> (see <FIG>) and absorb the shock.

In other cases, when any shock is applied to the printer cover <NUM> from outside, the hinge shaft <NUM> may slide along the body-side shaft-supporting long holes <NUM>, and the platen roller <NUM> may slide in the front-rear direction and absorb the shock while the platen shaft 10a is retained by the pair of arms <NUM> of the platen retaining bracket <NUM>.

Even under such a shock, the connection between body-side connector female terminals <NUM> and the cover-side connector male terminals <NUM> is maintained well for the following reasons.

The long axes of the body-side shaft-supporting long holes <NUM> extend in the front-rear direction so that the hinge shaft <NUM> slides in the direction perpendicular to the hinge shaft <NUM> in a plane horizontal to the outer bottom surface <NUM> of the printer <NUM>.

As described above, the body-side connector abutting surface <NUM> and the cover-side connector abutting surface <NUM> are horizontal relative to the outer bottom surface <NUM> of the printer <NUM>.

As shown in <FIG>, when the printer cover <NUM> is at the closed position, the orientation of the upward-displacement preventing surface <NUM> and the downward-displacement preventing surface 27p above and below the holding portion groove 27b is substantially the same as the orientation of the body-side connector abutting surface <NUM> and the cover-side connector abutting surface <NUM>.

Accordingly, even when any shock is applied from outside, status of the contact between the body-side connector abutting surface <NUM> and the cover-side connector abutting surface <NUM> hardly changes, and the contact between the body-side connector female terminals <NUM> and the cover-side connector male terminals <NUM> is maintained well.

The cover-side connector male terminals <NUM> are biased in the direction of increasing the length of the portions projecting frontward relative to the cover-side connector abutting surface <NUM>. Therefore, even when the distance in the top-bottom direction from the body-side connector abutting surface <NUM> to the cover-side connector abutting surface <NUM> varies due to a shock, a change in the projecting length of the cover-side connector male terminals <NUM> absorbs the distance variations. Thus, the contact between body-side connector female terminals <NUM> and the cover-side connector male terminals <NUM> is maintained well.

The printer <NUM> can be placed upright. That is, as shown in <FIG> and <FIG>, tip surfaces <NUM> of their respective body-side buffer members <NUM> and tip surfaces <NUM> of their respective cover-side buffer members <NUM> are provided. The printer <NUM> can be placed upright such as a planar face PL comprised of those tip surfaces is a bottom surface of the printer <NUM>.

For example, when the printer <NUM> is to be disposed on a plane not perfectly flat, or when the printer <NUM> is to be disposed upright on a slightly inclined plane, the hinge shaft <NUM> may slide along the body-side shaft-supporting long holes <NUM>. In this case, the printer cover <NUM> may slide relative to the body case <NUM>.

In such a case, due to the same reason as explained with reference to the shock absorption property, status of the contact between the body-side connector abutting surface <NUM> and the cover-side connector abutting surface <NUM> hardly changes, and the contact between the body-side connector female terminals <NUM> and the cover-side connector male terminals <NUM> is maintained.

Any modifications or changes that fall within the equivalent scope of claims are within the scope of the present invention.

For example, in the printer <NUM>, while it has been described that the platen shaft 10a has its position defined from four sides, namely, the top, bottom, front, and rear sides by the platen shaft retaining portions <NUM> and the platen retaining bracket <NUM>, the present invention is not limited thereto. The platen shaft retaining portions <NUM> may be removed, and the displacement of the platen shaft 10a may be restricted by the platen retaining bracket <NUM> alone. In this structure, as shown in <FIG>, the platen shaft 10a is also restricted in the top-bottom direction by two surfaces, namely, the upward-displacement preventing surface <NUM> and the downward-displacement preventing surface 27p. This precisely positions the body-side connector <NUM> relative to the platen shaft 10a when the printer cover <NUM> is closed. This enables accuracy in relative positioning of the body-side connector <NUM> and the cover-side connector <NUM>.

Claim 1:
A printer (<NUM>) comprising:
a body case (<NUM>);
a printer cover (<NUM>) configured to be openable and closable relative to the body case (<NUM>) about a rotary shaft (<NUM>);
a platen roller (<NUM>) that is rotatably attached the printer cover (<NUM>);
a print head (<NUM>) configured to pinch a print medium (<NUM>) with the platen roller (<NUM>) when the printer cover (<NUM>) is closed and perform printing on the print medium (<NUM>);
a first connector (<NUM>) disposed at a first position of the body case (<NUM>); and
a second connector (<NUM>) disposed at the printer cover (<NUM>) such that the second connector (<NUM>) is connected to the first connector (<NUM>) when the printer cover (<NUM>) is closed;
characterized in that
the printer (<NUM>) further comprises a platen retaining part (<NUM>) disposed at the body case (<NUM>) and configured to rotatably retain a first portion of the platen roller (<NUM>) at a second position of the body case (<NUM>) when the printer cover (<NUM>) is closed, the first position being in the vicinity of the second position, so that the platen retaining part (<NUM>) restricts displacement of the platen roller (<NUM>) in the top-bottom direction.